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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'Read-only' and 'Read-only metadata comparison.' It adds valuable behavioral context by stating no ranking data is invented and that it compares against the last seen state, which implies stateful persistence without explicitly detailing it.

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 focused sentences with no wasted words. The core purpose is front-loaded as 'Read-only competitor diff,' and the clarifying sentence adds meaningful constraints without redundancy.

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?

With no output schema, the description supplies the essential return shape: current listings, changes versus last seen state, and a digest line. It also covers the read-only nature and scope. It doesn't detail pagination or data freshness, but for a competitor-diff tool the description is reasonably complete.

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 100%, so the baseline is 3. The description adds mild context by saying competitor names are resolved, which aligns with the 'competitors' parameter, but it does not materially extend beyond the schema's parameter descriptions.

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 names a specific verb ('resolves'), a resource ('named competitors'), and the tool's purpose as a read-only diff. It also differentiates itself from ranking tools by explicitly stating no ranking-algorithm data is invented, making it distinguishable from siblings like rank_check.

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 clearly conveys when to use the tool: when you need current competitor listings, changes from last seen state, and a digest line. The read-only metadata comparison phrase and the exclusion of ranking data provide context, though no explicit alternatives are named.

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