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

No annotations are provided, so the description carries the full behavioral burden. It discloses what data is returned, which is useful, but says nothing about authentication, rate limits, cost, or what happens when the company/jurisdiction is unknown or invalid.

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?

Front-loaded with the core purpose in one sentence, followed by a compact Args block. No filler, though the Args formatting is slightly redundant with the schema structure.

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 read-only lookup with no output schema or annotations, the description covers what is fetched and how to identify the company, but omits failure behavior and jurisdiction format constraints. Adequate but with visible gaps.

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 0% (only bare titles), so the description must compensate, and it does: it identifies company_id as the 'OpenCorporates company number' and jurisdiction as a code with concrete examples ('us_de', 'us_ca'). This adds real meaning beyond the schema.

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?

States a specific verb ('Fetch') and enumerates the exact resources returned (officers, agent, filing history) for a company. The qualifier 'known company' implicitly separates it from sibling search tools like mcp_search_companies, though no sibling is named directly.

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?

'for a known company' hints that this is the lookup step after identification, implying mcp_search_companies would precede it. However, no alternative is named explicitly and no when-not-to-use guidance is given.

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