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

Annotations already declare readOnlyHint/destructiveHint, and the description agrees ("Read-only"), so no contradiction. Beyond that it adds real behavioral detail the annotations cannot: that delivery blockers are "shown under `delivery`, never merged into the letter," that `to_a` items carry file:line evidence for security findings and counts otherwise, and which conditions (red default branch, week-old red PRs, stale issues) constitute blockers.

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 purpose is front-loaded in the first clause, but the whole description is one long run-on sentence stitched together with em-dashes and parentheticals, forcing the reader to parse nested asides to extract the return shape. All the content is relevant to a no-output-schema tool, but it is dense and would read far better as a short list.

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 and only two simple parameters, the description carries the burden of explaining the return payload and does so thoroughly — letter, score, category breakdown, ordered `to_a` actions with evidence, separated `delivery` blockers, and the 30-day window. An agent knows what it will get and how the pieces relate; only pagination/size behavior is unmentioned, which is minor here.

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 (owner, repo) are documented in the schema itself. The description adds no syntax, format, or defaulting information for either parameter, so the schema does all the work and the baseline of 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 resource and output ("the repository's letter rating A+/A/B/C/D/F") plus everything bundled with it: score, six categories, `to_a` remediation list, `delivery` blockers, and 30 days of history. It also explicitly distinguishes itself by noting the grade is "the same number merjax_repo_health and the /health page show," so an agent can tell what this adds (grade + remediation plan) over the sibling.

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 context is clear and motivated: the "Owner mandate 2026-11-04: every repository should be A" plus the `to_a` payload tells an agent to call this when it needs to know how far a repo is from A and what concrete actions close the gap. What is missing is an explicit alternative statement — it never says when to prefer merjax_repo_health (the raw health report) instead of this graded view.

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