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

readOnlyHint=true already establishes this as a safe read, so the description's main addition is the REST endpoint mapping, which is mildly useful context. It does not disclose error behavior for a missing id, whether related hydration counts against limits, or the return shape. Adequate against existing annotations but not rich.

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, zero waste, with the core purpose front-loaded before the endpoint detail. Nothing to trim.

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-record read with full schema coverage, annotations marking it read-only, and no output schema, the description covers what an agent needs to invoke it. Only marginal gaps remain, such as error behavior for a non-existent id.

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 depth are already documented in the schema; the description only reinforces 'by id'. The depth parameter (hydration level 0-2), which is the more interesting one, gets no additional explanation beyond the schema. Baseline 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?

States a specific verb (Get), resource (person/contact), and scope (single, by id), which cleanly separates it from twenty_list_people and the other get_* siblings. The REST endpoint mapping (GET /rest/people/{id}) further pins down exactly what it does.

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 'single ... by id' phrasing implies usage versus list_people, but the description never explicitly states when to use this over alternatives such as twenty_list_people or twenty_get_company, nor any prerequisites. Usage is implied rather than stated.

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