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

Annotations already declare readOnly/idempotent/non-destructive/non-open-world, and the description adds real value beyond that: an explicit privacy guarantee ('Nothing sent is stored') and a statement of what comes back (status, findings with line numbers, fair-play checklist).

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 dense sentences with no filler; the core check behavior is front-loaded, the conditional secrets.md behavior next, and the return/privacy note last.

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?

No output schema exists, and the description compensates by naming the returned status, line-numbered findings, and checklist. Combined with full schema coverage and safety annotations, an agent has everything needed to call it correctly.

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%, so baseline is 3, but the description adds semantics the schema lacks: that supplying secrets_md conditionally unlocks the answer-key checks, including culprit-giveaway detection. Only the slug parameter's purpose is left solely to the schema.

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+resource: runs format checks on story.md and, when secrets.md is supplied, answer-key checks including culprit leakage. Clear what it does, though it never names a sibling (e.g. submit_story) to differentiate from, so a 4 rather than 5.

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?

Gives clear triggering context: use on a draft story.md, add secrets.md for the deeper fair-play checks. It doesn't explicitly exclude alternatives or say 'do not use for submission', so it stops short of the 5 bar.

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