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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false. The description adds real value beyond them: 'deactivate' signals a revocation (not physical deletion), the immediate-effect timing ('stops working immediately'), and the self-key guard. It stops short of stating whether the action is reversible or recoverable.

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?

Three short sentences with zero filler, front-loaded with the action and its effect, followed by the one blocking constraint. Every sentence earns its place.

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 single-parameter revoke tool with rich annotations and no output schema, the description covers action, timing, and the main precondition. It leaves minor gaps (reversibility, effect on existing records/audit, whether an error is returned for the in-use key), but nothing critical to invoking it correctly.

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% and the sole key_id parameter is fully documented in the schema, including its source ('from list_mcp_keys'). The description adds nothing parameter-specific beyond 'by its ID', so baseline 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?

States a specific verb and resource ('Revoke (deactivate) an MCP key by its ID') and clarifies the resource as an MCP key, which distinguishes it from the delete_api_key and delete_byok_key siblings. An agent can identify it without opening the 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?

It supplies a precondition ('Cannot revoke the key currently in use'), which is useful selection context, but never says when to choose this over delete_api_key or delete_byok_key, nor what to do instead if the key is in use. Implied usage only.

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