find_ctr_opportunities

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered and the bar is lower. The description still adds real behavioral value by disclosing the selection logic (CTR relative to position benchmark, not absolute CTR) and that each result carries an attached fix note, which the 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 sentences, zero filler, front-loaded with the selection criterion before the routing guidance. Every sentence earns its place.

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 read-only analytical tool whose annotations cover safety, the description plus full schema coverage is nearly sufficient; the mention of the per-page fix note partly compensates for the absent output schema. It does not sketch the returned fields (impressions, clicks, CTR, position), which would have closed the remaining gap.

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% with enum values for period and searchType, so the schema fully carries parameter meaning. The description adds no format, default, or interaction detail (e.g. how minImpressions affects recall), 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 (Find) plus the exact resource and selection criterion: pages whose CTR sits below the benchmark for their average position. It also names the distinctive output (a fix note per page), which differentiates it from the plain-ranking and query-level siblings.

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 an explicit trigger ('when the user asks which titles or snippets are wasting impressions') and then routes the agent away to two named alternatives with the conditions that select them (find_quick_wins for near-page-one query/page pairs, get_top_pages for a plain traffic ranking). Nothing 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.