diff --git a/AGENTS.md b/AGENTS.md
index 559b4baa3..4d1389904 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -65,6 +65,14 @@ Both notices recommend the same fix command: `lark-cli update`. The skills notic
 | `internal/vfs/` | Filesystem abstraction (use `vfs.*` instead of `os.*`) |
 | `internal/validate/path.go` | Path safety validation |
 
+## Auth / TAT operator notes
+
+- The current TAT path is documented inline in `internal/credential/`, `cmd/config/init_probe.go`, `cmd/auth/status.go`, and `internal/identitydiag/diagnostics.go`. Historical materials that talk about `SEC_AUTH` or `cmd/sec/*` should be treated as drift, not as current-tree entry points.
+- `config init` only performs a best-effort post-save probe. A typed auth error means the credentials were deterministically rejected; transport / timeout / parse failures are intentionally treated as ambiguous noise and do not prove the config is bad.
+- `auth status --verify` and runtime bot commands share the same credential chain. A successful bot verify confirms the current token source can call `/open-apis/bot/v3/info`, but it does not prove every downstream bot scope or API path will work.
+- Historical reports still matter: sandboxed runners may fail to read OS keychain state, and users can complete browser authorization while local state remains missing or stale. Treat those as environment / local-state risks to inspect, not proof that the remote authorization page never succeeded.
+- The notes above are derived from current mainline code plus historical reports. They are intentionally not a live verification guarantee; real token usability still depends on valid app config, local state, and network reachability.
+
 ## Who Uses This CLI
 
 This CLI's primary consumers include AI agents (Claude Code, Cursor, Gemini CLI). Your code is read by machines — error messages, output format, and flag design all directly affect agent success rates.
diff --git a/cmd/auth/status.go b/cmd/auth/status.go
index f0cf85e4d..e5d25085b 100644
--- a/cmd/auth/status.go
+++ b/cmd/auth/status.go
@@ -40,6 +40,10 @@ func NewCmdAuthStatus(f *cmdutil.Factory, runF func(*StatusOptions) error) *cobr
 	return cmd
 }
 
+// authStatusRun reports the configured identities. When --verify is enabled,
+// the bot branch does not mint a token independently — it reuses the shared
+// credential resolution path, so `auth status --verify` exercises the same TAT
+// source selection logic as normal bot API calls.
 func authStatusRun(opts *StatusOptions) error {
 	f := opts.Factory
 
diff --git a/cmd/config/init_probe.go b/cmd/config/init_probe.go
index e56aa1445..37d1cb0a7 100644
--- a/cmd/config/init_probe.go
+++ b/cmd/config/init_probe.go
@@ -28,6 +28,10 @@ const probeTimeout = 3 * time.Second
 // so that valid configurations and transient/upstream noise never block the
 // command.
 //
+// This is one of the repository's three main TAT entry points: config init
+// validates freshly-saved app credentials here, while runtime bot calls and
+// `auth status --verify` go through credential.ResolveToken.
+//
 // The function performs up to two HTTP calls in series, bounded by
 // probeTimeout:
 //
diff --git a/cmd/event/consume.go b/cmd/event/consume.go
index 0f8134b68..61dee8e0a 100644
--- a/cmd/event/consume.go
+++ b/cmd/event/consume.go
@@ -322,7 +322,10 @@ func sanitizeOutputDir(dir string) (string, error) {
 	return safe, nil
 }
 
-// resolveTenantToken fetches the app's tenant access token.
+// resolveTenantToken fetches the app's tenant access token for event consume.
+// This is a concrete runtime consumer of the shared bot-token path: event
+// consume does not own a separate exchange flow, it asks the credential layer
+// for the same TAT that other bot-mode commands use.
 func resolveTenantToken(ctx context.Context, f *cmdutil.Factory, appID string) (string, error) {
 	if ctx == nil {
 		ctx = context.Background()
diff --git a/extension/credential/env/env.go b/extension/credential/env/env.go
index 054d27d85..f3893f7e5 100644
--- a/extension/credential/env/env.go
+++ b/extension/credential/env/env.go
@@ -94,6 +94,9 @@ func (p *Provider) ResolveAccount(ctx context.Context) (*credential.Account, err
 	return acct, nil
 }
 
+// ResolveToken returns a token directly from environment variables. For bot
+// identity this is a straight TAT override that bypasses the built-in
+// app_id/app_secret mint path entirely.
 func (p *Provider) ResolveToken(ctx context.Context, req credential.TokenSpec) (*credential.Token, error) {
 	var envKey string
 	switch req.Type {
diff --git a/extension/credential/sidecar/provider.go b/extension/credential/sidecar/provider.go
index 99948939a..6fdb0ab37 100644
--- a/extension/credential/sidecar/provider.go
+++ b/extension/credential/sidecar/provider.go
@@ -103,6 +103,8 @@ func (p *Provider) ResolveAccount(ctx context.Context) (*credential.Account, err
 // ResolveToken returns a sentinel token whose value encodes the token type.
 // The transport interceptor reads this sentinel to determine the identity
 // (user vs bot), strips it, and the sidecar injects the real token.
+// In other words, sidecar mode proxies the normal UAT/TAT contract; it does
+// not introduce a new open-platform token-exchange protocol inside this repo.
 // Returns nil, nil when sidecar mode is not active.
 func (p *Provider) ResolveToken(ctx context.Context, req credential.TokenSpec) (*credential.Token, error) {
 	if os.Getenv(envvars.CliAuthProxy) == "" {
diff --git a/extension/transport/sidecar/interceptor.go b/extension/transport/sidecar/interceptor.go
index 6d928bd8a..8f87d443b 100644
--- a/extension/transport/sidecar/interceptor.go
+++ b/extension/transport/sidecar/interceptor.go
@@ -64,6 +64,9 @@ type Interceptor struct {
 // Supports two auth patterns:
 //   - Standard OpenAPI: Authorization: Bearer <sentinel>
 //   - MCP protocol:     X-Lark-MCP-UAT/TAT: <sentinel>
+//
+// For bot traffic the sentinel stands in for TAT only long enough for the
+// proxy hop; the real tenant access token is injected by the sidecar.
 func (i *Interceptor) PreRoundTrip(req *http.Request) func(resp *http.Response, err error) {
 	identity, authHeader := detectSentinel(req)
 	if identity == "" {
diff --git a/internal/credential/credential_provider.go b/internal/credential/credential_provider.go
index 8f20be11d..dbccf4280 100644
--- a/internal/credential/credential_provider.go
+++ b/internal/credential/credential_provider.go
@@ -301,6 +301,16 @@ func (p *CredentialProvider) doResolveIdentityHint(ctx context.Context) (*Identi
 }
 
 // ResolveToken resolves an access token.
+//
+// For bot identity this is the runtime TAT entry point used across the CLI:
+//  1. an active credential source (for example env or sidecar) gets first
+//     chance to return a token;
+//  2. extension providers are tried next;
+//  3. the built-in default provider falls back to FetchTAT(app_id, app_secret)
+//     and caches that tenant access token with sync.Once for the process.
+//
+// The env provider may supply a real TAT directly; the sidecar provider returns
+// a sentinel token that the transport layer rewrites into a proxied request.
 func (p *CredentialProvider) ResolveToken(ctx context.Context, req TokenSpec) (*TokenResult, error) {
 	source, err := p.selectedCredentialSource(ctx)
 	if err != nil {
diff --git a/internal/credential/default_provider.go b/internal/credential/default_provider.go
index 9482b2845..426510c9b 100644
--- a/internal/credential/default_provider.go
+++ b/internal/credential/default_provider.go
@@ -147,6 +147,8 @@ func (p *DefaultTokenProvider) resolveUAT(ctx context.Context) (*TokenResult, er
 }
 
 // resolveTAT resolves a tenant access token. Result is cached after first call.
+// This is the built-in runtime path behind bot token resolution when no
+// external credential source overrides it.
 // NOTE: Uses sync.Once — only the context from the first call is used.
 func (p *DefaultTokenProvider) resolveTAT(ctx context.Context) (*TokenResult, error) {
 	p.tatOnce.Do(func() {
diff --git a/internal/credential/tat_fetch.go b/internal/credential/tat_fetch.go
index eecaed20e..051d00937 100644
--- a/internal/credential/tat_fetch.go
+++ b/internal/credential/tat_fetch.go
@@ -18,6 +18,11 @@ import (
 // that already hold plaintext credentials (e.g. the post-`config init` probe)
 // can validate them without a second keychain round-trip.
 //
+// This is the built-in TAT mint path for the current repository:
+// app_id + app_secret -> /open-apis/auth/v3/tenant_access_token/internal.
+// It is reused by both the post-config probe and the default runtime bot-token
+// resolver. The tree does not contain a separate app_ticket-based TAT exchange.
+//
 // A non-zero TAT response code means the server inspected the payload and
 // rejected the credentials; FetchTAT returns the canonical typed error from
 // classifyTATResponseCode — the SAME classification doResolveTAT (and thus
diff --git a/internal/credential/types.go b/internal/credential/types.go
index 98af4d475..25dc818b1 100644
--- a/internal/credential/types.go
+++ b/internal/credential/types.go
@@ -97,6 +97,10 @@ type AccountProvider interface {
 }
 
 // TokenType distinguishes UAT from TAT.
+// In this repository, TAT always means "tenant access token" for bot identity:
+// either minted from app_id + app_secret by the built-in provider, supplied
+// directly by an extension provider, or proxied through authsidecar. There is
+// no app_ticket -> tenant_access_token exchange implementation in this tree.
 // Uses string constants matching extension/credential.TokenType for zero-cost conversion.
 type TokenType string
 
diff --git a/internal/identitydiag/diagnostics.go b/internal/identitydiag/diagnostics.go
index f8eb648d6..024362bce 100644
--- a/internal/identitydiag/diagnostics.go
+++ b/internal/identitydiag/diagnostics.go
@@ -217,6 +217,10 @@ func diagnoseUser(ctx context.Context, f *cmdutil.Factory, cfg *core.CliConfig,
 	return id
 }
 
+// resolveBotToken is the bot-verification consumer of the shared credential
+// chain. It intentionally reuses ResolveToken(core.AsBot, appID) so auth
+// diagnostics observe the same env-provider, sidecar, strict-mode, and
+// built-in FetchTAT behavior as normal runtime bot commands.
 func resolveBotToken(ctx context.Context, f *cmdutil.Factory, cfg *core.CliConfig) (string, error) {
 	if f == nil || f.Credential == nil {
 		return "", &credential.TokenUnavailableError{Type: credential.TokenTypeTAT}
diff --git a/main_noauthsidecar.go b/main_noauthsidecar.go
index 514afda63..3c4d7c1f8 100644
--- a/main_noauthsidecar.go
+++ b/main_noauthsidecar.go
@@ -8,6 +8,8 @@
 // compiled in under that tag; deploying the plain build into an environment
 // that expects sidecar isolation would silently fall back to direct env
 // credential use — exactly the failure mode the feature is meant to prevent.
+// Without the authsidecar build tag, the binary cannot safely proxy either UAT
+// or TAT through the sidecar contract at all.
 //
 // When LARKSUITE_CLI_AUTH_PROXY is set, we refuse to run rather than ignore
 // the variable. The operator either rebuilt without realizing (wrong