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

With no annotations, the description carries the full burden and does disclose real behavior: file list and diff are capped, 'truncated=true' signals a cut, and a memory:read scope is required. It defers error semantics to github_repo_get for 'same binding errors', which is informative but not self-contained.

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?

Three short sentences, front-loaded with the core action, then caveats (truncation) and prerequisites. No redundant text.

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?

An output schema exists, so return-shape explanation is unnecessary, and the description covers truncation semantics and auth requirements. The only gap is that error behavior is only cross-referenced rather than described.

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%, so both 'github' (owner/repo) and 'number' are already documented in the schema. The description adds no extra meaning about formats, ranges, or edge cases, so baseline 3 applies.

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 pull request') plus the scope of what is returned ('capped file list and diff'). An agent can distinguish it from github_pr_list or github_pr_checks, though no sibling is named 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?

Usage is implied by the required 'number' parameter and the prerequisite 'Requires memory:read', but the description never states when to reach for this versus github_pr_list (to find a number) or github_pr_checks (for CI status). Clear context, no explicit alternatives or exclusions.

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