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 description is not required to carry the safety profile. It adds genuine value by listing the response payload sections (contact data, status, files, custom fields) in the absence of an output schema, but it says nothing about error behavior for a missing id or about the mismatch between a 'candidate' resource and the /employees/{id} path.

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 verb and returned payload. The trailing 'GET /employees/{id}' is essentially redundant restatement of the operation, but the overall text is tight with no filler.

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 one-parameter read-only getter with no output schema, enumerating the returned fields is exactly the compensating detail an agent needs. Only minor gaps remain (not-found behavior, relationship to the per-aspect get_candidate_* siblings).

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% — candidate_id is documented as a numeric id — so the schema does the work. The description only echoes 'by id' and adds no format, type or validation detail beyond it, which is the baseline 3 case for a fully covered single parameter.

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 one candidate by id') and enumerates what is returned (contact data, status, files list, custom fields), which separates it from traffit_list_candidates. It stops short of naming siblings explicitly, and the 'files list' payload overlaps conceptually with traffit_get_candidate_files, so the boundary with that sibling is not fully resolved.

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 statement of when to use this versus traffit_list_candidates, traffit_get_candidate_files or the other get_candidate_* variants; the agent must infer that from the name alone. 'Scope: employee' is an API-doc fragment with no operational meaning for tool selection.

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