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

Annotations already set readOnlyHint=true, and the description adds valuable context beyond that: the authentication method (X-API-Key or Authorization Bearer), the expected output content (counts, copies, source), and the fact that this is only a summary, not detailed card data. No contradiction with annotations.

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 extremely concise—two sentences that front-load the primary purpose, then clarify when not to use the tool, and finally provide authentication details. Every sentence earns its place with no superfluous content.

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 that the tool has no parameters and an output schema exists, the description is fully complete. It covers the exact summary metrics, directs users to appropriate sibling tools, and explains authentication requirements—nothing critical is missing.

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 tool has zero parameters and the schema coverage is complete, so the baseline score of 4 applies. The description does not add parameter-specific details, but none are needed since there are no parameters.

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's function: summarizing the user's imported collection with specific metrics (distinct cards, total copies, import source). It also explicitly distinguishes itself from sibling tools by saying 'This is the SUMMARY only' and pointing to search_my_collection and what_can_i_build for other operations.

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 provides explicit when-to-use and when-not-to-use guidance. It states to use search_my_collection for individual card lookup and what_can_i_build for commander rankings, and it gives the API key requirement for invoking the tool.

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