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

With no annotations, the description carries the burden and does well: it discloses determinism, absence of LLM, the exact flag conditions, the conditional bugfix rule, and the single-PR limit. It stops short of saying what a finding/result looks like or whether 'pass' returns an empty list, which an agent needs to interpret results.

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?

Front-loaded with the identity of the tool and followed by an efficient rule enumeration; almost nothing is wasted. The single run-on sentence with stacked em-dashes makes the conditional bugfix rule slower to parse than a short list would.

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?

There is no output schema and the description never states the shape of the result (list of findings? per-rule messages? severity?), which is the main gap for a linter. Inputs and trigger conditions are otherwise well covered for a two-parameter tool.

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 both parameters are documented there, so the baseline is 3. The description adds only modest value beyond the schema: it mentions an explicit is_bugfix flag and that the issue reference is optional, but it does not explain the accepted forms of an issue reference (e.g., '#123' vs a ticket URL) or how body/title still influence the bugfix heuristic beyond the prefixes listed.

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?

Names a specific verb and resource ('PR description quality linter') and enumerates the exact rule set: short/missing body, missing test evidence, missing rationale, unstructured long body, bugfix-only repro steps, optional issue link. 'Single PR only, no batch' and 'no LLM' further pin down what it is versus lint siblings like ticket_lint or commit_hygiene.

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?

Explicitly scopes usage ('Single PR only, no batch') and states the conditional trigger for repro-step checks (title prefix fix/bug/hotfix/patch, or is_bugfix). It does not name an alternative tool to use instead when the PR is part of a batch or when a broader ticket check is wanted, so routing to a sibling is left to inference.

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