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

With no annotations, the description carries the full burden. It discloses the critical behavior that the analysis runs client-side and is not server-callable, but does not mention other behaviors such as error handling, privacy implications, or what happens with invalid inputs.

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 concise: two sentences that front-load the purpose and immediately follow with the critical limitation. Every sentence is necessary and there is no extraneous information.

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?

Given no output schema and no annotations, the description adequately covers the tool's purpose, its limitation (client-side analysis), and what it returns (guidance and a link). It is complete enough for an agent to understand the tool's role, though it could mention expected output structure or error scenarios.

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 schema has one optional parameter (image_url) with clear description. The tool description adds value by explaining that the parameter is merely informational because the analysis runs in-browser, which is beyond the schema's description.

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 clearly states the tool estimates centering and rough PSA-style grade from a photo, but then clarifies that the actual analysis runs client-side, making the tool's direct purpose more about providing guidance and a link rather than performing the estimation itself.

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 does not provide any guidance on when to use this tool versus its siblings (check_in_stock, check_recall, etc.), which are unrelated. It only notes a limitation (not server-callable) but no explicit 'when-to-use' or 'when-not-to-use' advice.

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