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

Annotations already flag destructive/non-idempotent, but the description adds genuinely new behavior: admin access is required, org-visible files remain visible to all members after the grant is removed, and the call is free with API-key or connected-account auth. It does not say what happens when the grant id is unknown or whether access revocation is immediate.

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?

Front-loaded with the action, then permissions, then edge-case semantics, then cost/auth. Extremely dense telegraphic clauses ('Free.') are efficient but make it read like notes rather than prose; nothing is wasted, though.

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 two-parameter destructive mutation with no output schema, it covers auth, admin requirement, the key side-effect caveat (org visibility persists), and the remedy path. Only the failure/response behavior is unspecified.

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?

Schema coverage is only 50% — grant_id has no schema description, and the description supplies its provenance ('from get_file'), which is real added meaning. The file 'id' parameter is already documented in the schema, so the description need not repeat it.

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?

States a precise verb+resource with granularity: 'Removes one share of a library file by its grant id.' The emphasis on 'one share' (versus deleting the file or all sharing) lets an agent distinguish this from delete_file and share_file without opening either schema.

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?

Gives the triggering context clearly (revoke a single grant obtained from get_file) and names a follow-up alternative path via update_file for org-visible files. It does not explicitly say when to prefer delete_file or a full unshare-all, so it stops short of full alternative routing.

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