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

readOnlyHint=true already declares this as a safe read, so the bar is lower. The description adds only the API endpoint mapping and nothing about 404/not-found behavior or what a failed lookup returns; it neither contradicts nor meaningfully extends the annotation.

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 sentences, front-loaded with the action and scoped by id, followed by the exact endpoint for cross-reference. No filler at all.

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 read with full schema coverage and annotations declaring read-only status, this is nearly complete. The only gap is that with no output schema, nothing hints at the shape or size of the returned company object.

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 parameters are documented in the schema itself. The description adds no field-selection syntax guidance for the 'fields' parameter or id format, which is acceptable given the schema carries the load.

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 ('Get a single company by id') plus the underlying REST endpoint, so the agent knows exactly what is fetched. It never names the sibling it must be distinguished from, notably keap_list_companies, so differentiation is left to inference.

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?

Usage is implied by 'by id' versus the list variant, but there is no explicit when-to-use statement, no precondition, and no named alternative. An agent can infer the case, but the description does no routing work.

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