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

Annotations already declare the tool is read-only, idempotent, and non-destructive. The description adds useful context about the exact data returned (skill counts, accountant-verified counts, named lead verifier) and implies no pagination. This goes beyond the annotations and the empty schema, so it earns a solid score.

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 two sentences, front-loaded with the core purpose and return content, followed by usage examples and a comparison to a sibling. Every sentence earns its place with no filler, making it highly concise and well-structured.

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 zero-parameter list tool with an output schema, the description explains what data the tool returns (including specific counts and verifier names), provides trigger examples, and notes the alternative. Nothing essential is missing; the output schema covers the return format, so the description is 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?

The tool has zero parameters, so the schema fully defines that there are no inputs. The description adds no parameter details because none are needed. Per the calibration rule for 0 params, the baseline is 4, and the description meets it without extraneous information.

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 states a specific verb ('Returns'), a clear resource ('every jurisdiction with published skills'), and detailed content (countries, US states, Canadian provinces, with counts and verifier). It also explicitly distinguishes itself from a sibling tool ('Avoids paginating through list_skills to compute this'), making its purpose unambiguous.

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 example queries that trigger this tool ('which countries does OpenAccountants cover?' or 'what's available for [country]?'), and it references a sibling alternative (list_skills) that it avoids. It does not enumerate exclusions for other sibling tools, but the examples and the alternative mention give solid practical guidance.

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