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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds no further behavioral context such as error behavior for a missing/invalid ID, which is the only notable gap left for a read tool.

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?

A single eight-word sentence with the resource and lookup key front-loaded. Nothing extraneous and 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 trivial single-parameter read tool with complete schema coverage and read-only annotations, the description is largely sufficient. Only minor gaps remain (behavior on a non-existent ID, relationship to the list variant), which is acceptable at this complexity level.

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% and the single 'id' parameter is documented with its type, UUID format and pattern, so the schema does the heavy lifting. The description only restates 'by ID' and adds no format or constraints beyond what is already structured.

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 a single project time entry') plus the lookup key ('by ID'), so the agent knows it is a point fetch rather than a list. It does not explicitly name the sibling list_project_time_entries, so differentiation is implied by 'single' rather than stated.

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?

No when-to-use guidance, no prerequisites, and no mention of the alternative (list_project_time_entries) for retrieving multiple entries. The agent must infer that this is the right tool only when it already has a specific ID.

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