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

With no annotations supplied, the description carries the full behavioral burden, and it does deliver one important trait: idempotency if already revoked, which tells the agent retries are safe. It still omits whether revocation is permanent or reversible, whether tokens issued under the credential are invalidated immediately, and what a repeated call returns.

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 sentences, with the action and resource front-loaded and the idempotency guarantee placed second where it answers the agent's natural follow-up concern. No filler or redundant restatement of the tool name.

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 mutation tool with no output schema, the definition covers the essentials: what is revoked, required scope, and retry safety. The remaining gap is the post-condition — whether the credential and any associated keys become unusable and whether the action is reversible — which an agent might want before calling.

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 100% for the single required credentialId, whose type and description are already documented in the schema. The description adds no meaning about where to obtain a vault credential id (search_credentials is a plausible source but is not referenced), so the baseline of 3 applies.

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 gives a specific verb plus resource, "Revoke a vault-scoped credential," which is unambiguous against create_vault_credential and update_vault_credential without opening their schemas. It does not explicitly name an alternative (e.g., update_vault_credential for rotate/disable), so it stops short of full sibling differentiation.

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?

The parenthetical "(treasury + keys:manage)" communicates a real usage prerequisite, telling the agent what scope context it needs. However, there is no explicit guidance on when to revoke versus rotate via update_vault_credential, and no stated exclusions or preconditions such as checking whether the credential is in active use.

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