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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description doesn't need to repeat safety. It adds valuable behavioral context: the lever is framed as 'the change most associated with improvement' (not a guarantee), includes disclaimers about non-advice, and mentions a link to a 'claim your score' page. This goes beyond annotations and enriches the agent's understanding of what the tool returns.

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 front-loaded with the main purpose, then expands on input formats, output components, and disclaimers. Each sentence contributes useful information. It is slightly redundant by repeating area formats already in the schema, and the legal disclaimers add length, but overall it remains well-structured and not overly verbose.

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 simple 1-parameter tool with an output schema present, the description is exceptionally complete. It explains the input formats, the exact output (highest-impact lever, approach, link), the nature of the guidance (aggregated, non-guaranteed), and the read-only/no-personal-data characteristic. With an output schema handling return structure, no significant gaps remain.

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 description for the 'area' parameter is 100% covered with format examples (ISO-3166, NUTS-2, CBS GM-code) and case-insensitivity. The tool description repeats this information without adding new meaning about the parameter itself. Therefore, the description adds no significant value beyond the schema, warranting the baseline score of 3.

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 opens with 'Return constructive improvement guidance for one area,' a specific verb+resource+scope that immediately clarifies the tool's function. It distinguishes itself from sibling tools by emphasizing 'one area' and detailing the output (highest-impact lever, Fynqo's approach, link), making it clearly different from statistics or comparison tools.

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 implies when to use this tool: when you need improvement guidance for a single area. It provides context about input formats and output, and states 'Read-only, no personal data,' which further clarifies appropriateness. However, it lacks explicit exclusions or named alternatives, so it falls short of a 5.

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