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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description need not repeat that it mutates state. It adds useful behavioral detail by noting that the post "leaves the default search" and that it must be "one of your posts," implying ownership. It does not explain whether the close is reversible, leaving a minor gap.

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?

The description is a single, front-loaded sentence with no wasted words. The parenthetical condition is compact and informative. It is appropriately sized for a simple one-parameter tool.

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 simple mutation tool with no output schema, the description covers the action, effect, and ownership context reasonably well. However, it does not fully compensate for the missing parameter description or clarify whether the close is permanent. The annotations cover the safety profile, but the id semantics remain underspecified.

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?

The single parameter id has 0% schema description coverage, so the description must carry the burden. It implies the id identifies "one of your posts," but does not explicitly state that it is a post ID or describe its format. This is a clear gap for a required parameter.

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 states a specific verb and object: "Close one of your posts." It adds scope and effect ("leaves the default search"), making the action clear. However, it does not explicitly distinguish this from the sibling listing_close, which could be confused with market_close.

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 description gives clear usage context: close a post when it is "filled, or no longer offered." This is enough to know when to invoke the tool. It does not mention alternatives such as listing_close or market_search, but the primary condition is stated.

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