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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description is not carrying the safety profile alone. It does add real value beyond them by scoping the destruction: history survives unless purge is true. It could go further on reversibility or what happens to the tracking record itself.

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 waste, with the core action front-loaded and the destructive conditional immediately after. Nothing could be cut without losing meaning.

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 two-parameter mutation with no output schema, annotations covering the safety profile, and full schema coverage, this is close to sufficient. The remaining gap is minor: no return/confirmation behavior and no statement of what the untracked record leaves behind.

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%, so baseline is 3. The description's "unless purge is true" restates what the schema's own purge description ("Delete the rank history too.") already conveys, adding no syntax or edge-case detail beyond it.

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?

"Stop tracking a keyword" gives a specific verb (stop tracking) plus the resource (keyword), clearly the inverse of track_keywords in the sibling list. It stops short of naming the inverse sibling explicitly, so it lands at 4 rather than 5.

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 intent is inferable from the name and the sentence, but there is no explicit when-to-use/when-not guidance and no pointer to the counterpart tool (track_keywords) or to list_keywords for obtaining the id. Usage is implied rather than stated.

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