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

The readOnlyHint annotation already declares this is a safe read, so the description only needs to add context, and it does contribute the REST endpoint mapping (GET /rest/companies/{id}) which helpers integrating with the REST API. However, it says nothing about behavior on a missing/invalid id, nor what the 'depth' hydration actually returns.

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, front-loaded sentences with zero waste: the core action leads, the endpoint follows as supporting detail. Nothing needs to be trimmed or reordered.

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?

With full parameter coverage and a readOnly annotation covering the safety profile, the essentials are present. But there is no output schema, and the description does not say what a returned company record contains — a gap it could have filled given that omission.

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%: both 'id' and 'depth' (with 0-2 bounds and its hydration meaning) are fully documented in the schema. The description adds no parameter detail beyond what the schema already provides, so the baseline of 3 is appropriate.

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 names a specific verb and resource ('Get a single company by id') and adds the underlying REST route, so an agent knows exactly what it does. It implicitly distinguishes itself from twenty_list_companies by saying 'single ... by id', though it never names or contrasts that sibling explicitly.

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 phrase 'by id' implies the precondition (you must already have a company id), which is the minimum viable usage signal. There is no explicit when-to-use versus twenty_list_companies or twenty_list_metadata_objects, and no exclusion guidance.

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