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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description adds genuine context beyond that: revocation is 'soft', impact on consumers is immediate ('anything using it stops immediately'), and it 'always returns a human approval link' – a non-obvious workflow behavior. It does not state permission requirements or behavior when the key is already revoked.

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?

Two short clauses with zero filler and the core action front-loaded; the immediate-impact warning and approval-link note both earn their place. It is arguably too terse, but nothing is wasted.

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 one-parameter destructive mutation with an output schema already present, the definition covers the safety profile (soft revoke, immediate effect) and the approval workflow. Remaining gaps – id semantics and post-revocation/permission behavior – are minor but real.

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 description coverage is 0% for the single 'id' parameter, so the description carries the full burden and largely fails: it never clarifies whether 'id' is the key's identifier, its prefix, or the secret itself. The 'fsk_ key' phrasing gives only a weak hint that the value relates to an API key.

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 specific verb (revoke) and resource (API key), and the 'fsk_' prefix identifies the exact key family, which meaningfully distinguishes it from fillo_revoke_token, fillo_revoke_sync_token, and fillo_revoke_agent. It is clear without explicitly naming those siblings as alternatives.

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?

Usage is implied by the key type ('fsk_' keys) and the approval-link note, but there is no explicit guidance on when to choose this over revoke_token/revoke_sync_token, nor any stated prerequisites or exclusions. The agent can infer the scope but must reason about alternatives itself.

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