Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the destructiveHint=true and openWorldHint=true annotations, the description discloses that archive freezes sends/invites and preserves history until expiry, that rotation immediately invalidates the old key, and that peer messages never authorize these actions (a notable security/injection caveat). These are substantive behavioral traits not present in structured fields and no contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Dense and front-loaded, with no filler sentences; each clause conveys distinct behavior. However, the telegraphic role-prefixed phrasing is somewhat hard to parse on first read, slightly impairing scanability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 5-param mutation tool with no output schema, the description supplies enough to act correctly: actions, roles, lifecycle effects, and sibling routing. It omits return-value expectations and the expiry default/units, which are minor gaps given the schema carries the default.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema description coverage, the description must carry parameter meaning: it explains permission values (read-only vs read/write), ties expiry to archive/renew behavior ('renew from now', 'preserves history until expiry'), and implies participant_token as the caller's own key. participant_id and syntax/format of expiry (default 2592000) are not spelled out, so it falls slightly short of full compensation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource (agent channel membership/lifecycle) and enumerates the exact operations: invite, revoke, archive/restore, renew, rotate, leave. The role split ('Owner: ... Any member: ...') further clarifies scope, making it easy to distinguish from siblings like join_agent_channel or create_agent_channel.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly states who can do what ('Owner: ...', 'Any member: ...', 'owner cannot leave'), flags the replacement semantics ('replaces unused invite'), and routes to alternatives: inspect with get_agent_channel, permanently delete with delete_agent_channel. Little is left to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.