keyword_volume

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

With no annotations present, the description carries the full burden and does so: it discloses that this is a paid x402 service settled in USDC on Base, that the calling MCP server needs a funded wallet, the fixed $0.15 price, and the 402 failure mode when unpaid. It also states the request shape (POST `{ keywords }`), which is unusual and otherwise undiscoverable from the schema alone.

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 tight sentences, front-loaded with the output content, then the batching/cost rule, then the payment mechanics. Every clause carries distinct information — no restatement of the tool name or filler.

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?

There is no output schema and no annotations, so the description must cover return values and safety/commercial behavior — it names the returned metrics and trend window and explains the payment flow and failure code. For a 3-parameter read tool this leaves nothing material an agent needs before calling it.

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 (keywords, language, location) are already documented, and the description only restates the 200-keyword cap and per-call pricing. It adds no meaning for the language or location parameters beyond what the schema says.

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: monthly search volume, CPC and competition for a batch of keywords, plus a 12-month trend per term. The returned metrics are named explicitly, so an agent knows exactly what it gets without opening the schema. It is distinguishable from seo-oriented siblings such as ranked_keywords or keyword_ideas by being a batch volume/CPC lookup.

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 concrete operational guidance: batch up to 200 keywords in ONE call because pricing is per call, not per keyword — that directly shapes how an agent should invoke it. It does not name an alternative sibling or state when-not to use it (e.g., single-keyword or idea-generation needs), so it stops short of full routing guidance.

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