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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds real value by enumerating the returned fields and naming the underlying endpoint (GET /2/users/{id}), which compensates for the absent output schema. It does not mention error behavior for a missing id, keeping it short of a 5.

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 tight clauses, zero filler, with the core action front-loaded and the endpoint reference last. Every element earns its place.

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 tool with no output schema, listing the returned fields plus the API endpoint gives the agent enough to invoke and interpret the call. Only the not-found/error behavior is left 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% for the single user_id parameter, so the schema already documents it fully. The description's 'by id' adds no syntax, format, or constraint detail beyond what the schema provides, matching the baseline 3.

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 one user by id') and enumerates the returned fields (name, email, role, positions, schedules, wage), which cleanly separates it from the sibling list_users. An agent can identify the operation without opening the schema.

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 'by id' phrasing implies you already have a user_id, which implicitly excludes the list/eligible-users siblings, but the description never explicitly names when to use this versus wheniwork_list_users or wheniwork_list_eligible_users_for_shift. Usage is inferable but not stated.

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