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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the list of returned fields and an authentication note, which is useful context. However, the auth note is somewhat ambiguous ('Authenticated callers only (the read tool surface still works anonymously)') and could confuse. It does not disclose error behavior, rate limits, or any side effects, but for a read tool with annotations, the additional field list provides reasonable value.

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?

The description is a single sentence with no wasted words, and the action verb is front-loaded. The parenthetical about authentication adds a necessary caveat but is slightly awkward. It is efficient and readable, though the ambiguous auth phrasing slightly detracts from clarity.

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?

With no output schema, the description compensates by listing the exact fields returned (title, body, state, branches, draft, author, timestamps), which is essential for an agent to know what it gets. For a simple read operation with annotations covering safety, this is largely complete. The auth note, while confusing, does alert the agent to a requirement. Missing details like error handling are minor for a read tool of this simplicity.

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% – each parameter (owner, repo, number) has a clear description. The tool description adds nothing about parameter semantics beyond what the schema provides. It lists the fields returned but not any parameter-specific details. Baseline 3 is appropriate when the schema fully documents parameters.

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?

The description clearly states the verb 'Fetch' and the resource 'full detail record of a pull request', and enumerates the fields returned (title, body, state, branches, draft, author, timestamps). This distinguishes it from sibling tools like gluecron_list_prs, gluecron_search_prs, and gluecron_get_diff, which serve different purposes. The specificity leaves no ambiguity about what the tool 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 description provides no guidance on when to use this tool versus alternatives like list_prs or search_prs. The only usage note is the authentication requirement, which is about caller eligibility rather than tool selection. An agent would have to infer that this is for a single PR by number based on the schema, but the description does not explicitly state selection criteria.

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