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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the underlying endpoint mapping (GET /companies/{id}), which is mildly useful for agents mapping to API behavior, but it says nothing about what happens with an invalid or unknown id.

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 short fragments with zero filler and the key information (single company, id-based) front-loaded. The HTTP path restatement is marginally redundant but cheap and aids API mapping.

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 single-entity fetch with full schema coverage and clear read-only annotations, this is minimally adequate. With no output schema, though, a hint about what a company record contains or how a missing id is surfaced would have closed the remaining gap.

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 coverage is 100% and the single company_id parameter is documented as "CATS company id" with a positive-integer constraint. The description's "by id" adds nothing beyond the schema, so baseline 3 applies.

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?

"One company by id" states a specific verb (fetch a single company) and resource, and the "by id" qualifier implicitly distinguishes it from cats_list_companies and cats_search_companies. It is clear but relies on the name and sibling context rather than explicitly naming the alternatives.

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?

There is no guidance on when to use this versus cats_list_companies or cats_search_companies, and no mention of prerequisites such as needing a valid company id. The usage is only inferable from "by id" and the tool name.

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