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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It lists outputs and a query format, but does not disclose input size limits, encoding requirements, error behavior, rate limits, or whether the keyword parameter affects all metrics. This is thin for a tool with zero annotation coverage.

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 description is compact and front-loads the output metrics before the query format and price. It earns its place with useful detail, though the 'HTTP x402 price' fragment is slightly cryptic and could be clearer.

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?

The output schema exists, so return-value structure is covered elsewhere. For a simple single-purpose utility, the core capability is stated, but the missing usage guidance and absence of behavioral caveats leave an agent to infer when and how to call this versus sibling text tools.

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 0%, so the description must compensate for the text and keyword parameters. It does add some meaning by showing '?text=<text>&keyword=' and implying keyword is used for keyword density. However, it does not explain whether parameters are optional, how they interact, or any constraints beyond the schema's nullability.

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 subject ('Text readability') and enumerates the exact outputs it produces: Flesch score, level, average sentence length, keyword density, and top words. This distinguishes it from sibling utility APIs, though it lacks an explicit verb like 'computes' or 'returns'.

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 provides a URL template and price but gives no guidance on when to prefer this tool over alternatives, such as api_text_stats. It does not mention any exclusions, prerequisites, or limiting conditions for when this tool is appropriate.

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