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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds genuinely new behavioral context that annotations cannot express: the key keeps working for a few minutes after deletion, which sets correct expectations about propagation delay.

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, zero filler, with the core action stated first and the useful timing caveat second. Every clause 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?

An output schema exists, so return values need not be described. The definition covers the action and its delayed effect; the only material gap is the undocumented account_key parameter and the lack of any note on irreversibility beyond what the destructive annotation implies.

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 two parameters. The description compensates for key_id by telling the agent it comes from get_account, but account_key is left completely unexplained in both schema and description. Partial compensation warrants a mid score.

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 and resource ('Delete an API key of your account'), which is unambiguous and inherently distinguishable from the sibling create_api_key. An agent knows immediately what operation this performs.

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 '(key_id from get_account)' points the agent at the sibling that supplies the required parameter, which is useful routing. However there is no explicit when-to-use/when-not guidance, e.g. no warning about deleting the key currently in use or whether a replacement key should be created first.

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