Count companies matching a name/filter (IE only)

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

Annotations declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true. The description adds critical behavioral context beyond annotations: it warns that the endpoint is NOT cheaper than search_companies, that it runs the same underlying query, and that other jurisdictions return 501. This fully leverages the description to disclose behavior.

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 well-structured with sections for jurisdiction-specific notes and performance notes, and uses Markdown for readability. Every sentence adds value, but it is slightly longer than necessary; some detail about the 501 return could be shortened. Still, overall efficient.

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 the tool's complexity (7 parameters, 1 required, output schema exists), and the sibling context, the description is complete. It explains the tool's purpose, performance, jurisdiction support, and relationship to search_companies. No gaps identified.

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?

Schema description coverage is 29% (only jurisdiction and query have descriptions). The description does not add meaning for most parameters beyond what the schema provides, but it does mention that it supports the same filters as search_companies, which is helpful context. Baseline 3 due to low coverage, but the mention of shared filter semantics raises it to 4.

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 starts by clearly stating what the tool does: 'Return the total number of companies that would match a search, without fetching the candidates themselves.' This is a specific verb + resource combination, and it distinguishes the tool from siblings like search_companies by emphasizing that it only returns a count.

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 explicitly tells when to use this tool ('when the raw count is what you actually need') and when not to use it ('for 'is this query narrow enough to paginate?', it's faster to call search_companies with limit=1'). It also provides an alternative and explains performance trade-offs.

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