Best performance

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

Annotations declare readOnlyHint, idempotentHint, openWorldHint, and the description adds behavioral context (preference for largest sample and EUR, returns parsed effect sizes and metrics). No contradiction. Disclosing the return types enhances transparency.

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 sentences, front-loaded with purpose and constraint, followed by return details. No extraneous words or repetition. Every sentence adds value.

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 an output schema exists, the description adequately covers the tool's purpose, constraints, and return types. It does not mention prerequisites for pgs_id, but is otherwise complete for a single-parameter read-only tool.

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 only parameter pgs_id is not described in the text, and schema description coverage is 0%. The description should explain what pgs_id represents (e.g., a score identifier) to compensate, but it does not, leaving a significant gap.

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 uses a specific verb ('look up') and identifies the resource ('best evaluation performance') with clear constraints ('largest sample, EUR-preferred'). It distinguishes from sibling tools like search_scores and score_info by focusing on performance.

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 implies usage for retrieving top performance metrics for a single score, but does not explicitly state when to use versus alternatives. Sibling tool names provide enough context, but a direct usage hint would improve clarity.

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