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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description does add useful context beyond the annotation: the underlying endpoint and the { meta, response } return envelope. It omits error behavior (e.g. unknown id) and pagination/field-expansion caveats.

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?

Three short sentences, front-loaded with the purpose before the endpoint detail and return shape. Nothing is wasted, though the raw API path is the least agent-relevant element.

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-resource getter with no output schema, stating the return envelope { meta, response } compensates reasonably for the missing output schema, and the endpoint confirms it is a plain read. Only error/empty-result behavior is unaddressed.

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 100%, so both 'id' and 'fields' are already documented in the schema. The description adds no parameter-level meaning (no id format, no note on when _ALL is expensive), so the 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?

States a specific verb and resource ('Fetch a single company') and the parenthetical '(client organization)' disambiguates the domain term. The word 'single' implicitly separates it from list_companies, but no sibling is named explicitly, which is the difference between a 4 and a 5.

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 when-to-use guidance: nothing says to use this for one known id versus list_companies for browsing, and nothing covers the 'fields' parameter as an optional expansion. Usage is only implied by the verb.

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