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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description contributes only the REST endpoint mapping; it says nothing about missing-id/404 behavior, auth requirements, or whether the response includes expanded relations.

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 telegraphic fragments with zero waste and the key semantics front-loaded. It is compact to the point of being skeletal, but nothing is redundant.

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 single-parameter, read-only getter with full schema coverage and annotations covering the safety profile, this is close to sufficient. Only failure-mode and response-shape context is absent, which is minor given no output schema expectation.

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 coverage is 100% and the single user_id parameter is documented in-schema with an example format. The description reinforces that the id is the sole lookup key ('by id') but adds no format detail beyond the schema.

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) and resource (user) plus the lookup key (id), and the endpoint mapping confirms it is a single-record fetch. It implicitly contrasts with upkeep_list_users but never names 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?

'One user by id' implies use when a single known id is available, so usage is inferable rather than stated. There is no explicit when-not guidance or pointer to upkeep_list_users for discovery-type lookups.

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