gsc_opportunities

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely non-obvious context: results are heuristics, not official errors, which sets the right expectation about reliability. It stops short of describing ranking/ordering or what fields come back.

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?

A single tight sentence with no filler, front-loading the core criteria (low CTR in top 10, position 10-20) and appending the heuristic caveat. Efficient, though the caveat could be integrated more cleanly.

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 five parameters, no output schema, and sparse schema descriptions, the definition leaves too much unexplained: no return shape, no ordering, no interaction between minImpressions and the position bands, and no note on how limit applies. For a diagnostic tool that returns a ranked opportunity list, this is insufficient context.

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 only 60%; limit and minImpressions carry no schema descriptions and are never mentioned in the description at all, leaving their purpose (result cap, impression floor) unexplained. The description also adds nothing about siteUrl, the date range, or how the position-band criteria interact with minImpressions, so it fails to compensate for the coverage gap.

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 recognizable analytical purpose: surfacing queries worth investigating due to low CTR in the top 10 or average position 10-20. The verb is implicit (an analysis/diagnostic query) rather than explicit, and it never names the sibling analytical tools (gsc_query_advanced, gsc_search_performance) it should be distinguished from, but the criteria are concrete enough that an agent can identify the tool's job.

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?

The description implies the scenario (finding under-performing queries within certain CTR/position bands) but offers no explicit when-to-use vs when-not guidance and no reference to alternatives. An agent must infer that this is the tool for heuristic opportunity discovery rather than raw performance retrieval.

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