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

Annotations already declare readOnlyHint=false and destructiveHint=false, and the description goes well beyond them: it discloses that nothing is published to the App Store or Google Play, that ranks from the run become the baseline for weekly reports, and that the call consumes the monthly draft-save allowance. Quota consumption and the baseline side effect are exactly the kind of non-obvious behavior an agent cannot infer from structured fields.

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, each earning its place: what it does, what it does not do, and what it costs. The core action is front-loaded and the safety caveat follows immediately.

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?

For a non-idempotent mutation with no output schema, the description covers the write scope, the non-publication guarantee, the quota cost, and the rank-baseline side effect. It does not say what identifier or object the draft returns on success, which is the one remaining gap for a tool whose callers will likely need the draft id for follow-up.

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 the schema already documents all four parameters, including 'variant_id from wow_keywords_get'. The description reinforces the variant/run relationship but adds no format, constraint, or default details beyond the schema, so the 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: save one variant of a finished Wow Keywords run as a metadata draft of the tracked application, plus the side effect of recording baseline ranks. This is clearly distinguishable from run/report/get siblings and from the generic save_metadata_draft, since it is scoped to a Wow Keywords run variant.

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?

'One variant of a finished Wow Keywords run' establishes the precondition (the run must be complete, and the unit of work is a single variant, not the whole run). It does not explicitly contrast with the sibling save_metadata_draft or state when a caller should prefer one over the other, which keeps it short of a 5.

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