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

With no annotations, the description carries the behavioral disclosure burden. It does disclose the output quantity ('5-10 relevant keywords') and the pay-per-use cost, but it does not describe the output representation, failure behavior, or whether empty/short inputs are handled acceptably.

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?

The first sentence is front-loaded, informative, and concise, but the rest adds some non-essential detail. The phrase 'input=text' is partially redundant with the schema, and the payment line is useful but auxiliary, making the whole description slightly cluttered.

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 single-parameter text-in/text-out extraction tool, this description provides what an agent needs: purpose, input, output quantity, and cost. Since there is no output schema, noting the output format explicitly would have been ideal, but the tool is simple enough that the remaining gap is minor.

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?

The input schema already documents the only parameter at 100% coverage, so the description is not required to compensate. The description's 'input=text' adds clarity for humans but no meaningful meaning beyond the schema's provided property description.

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?

The description states a clear verb ('Extract'), a specific resource ('keywords'), an input source ('from a text'), and an expected quantity ('5-10'), making the tool's purpose obvious. The SEO/indexing qualifier adds context, though the description does not explicitly distinguish keywords from closely related sibling tools like entities.

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 parenthetical '(SEO/indexing)' gives the intended usage context, and the title itself makes the extraction task clear. However, there is no explicit guidance about when to prefer this tool over similar text-analyzing siblings, nor are alternative tools named.

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