keyword_overview

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

Annotations already declare read-only, open-world, non-destructive, so the safety profile is covered; the description still adds substantial context the annotations cannot express — credit cost band (10-116, scaling with keyword count), the 1000-keyword cap, country-level volume scoping, and that null means no data rather than zero. That is exactly the kind of extra context that earns full marks against an annotated tool.

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?

Front-loaded with the trigger condition and the sibling contrast, and every sentence carries information (output fields, cap, cost, null semantics). The one long parenthetical enumerating backlink fields is dense and slightly hard to scan, which keeps it from a 5.

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?

Covers limits, cost, scoping caveats, and null handling, and the tool has an output schema so return shapes need not be spelled out — yet the description still previews the key fields. An agent has everything needed to decide and call 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 description coverage is 100%, so all three parameters are already documented and the baseline is 3. The description reinforces the 1000-keyword limit and the country-level scoping of location, but adds little syntax or format detail beyond what the schema states, and includes no guidance on language fallback behavior.

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?

Names a specific resource (keywords) and enumerates the exact payload it returns: volume, CPC, competition, keyword_difficulty, search_intent, and the averaged backlink profile. It explicitly contrasts itself with the sibling search_volume, so an agent can separate the two without opening either schema.

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?

Opens with a trigger condition ("Use when you have keywords and want the full picture on them") and names the alternative plus the precise condition that selects it ("use search_volume instead when the city/state number is what matters"). Both when-to-use and when-to-use-something-else are stated.

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