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

The description discloses that page content is not stored, but it doesn't disclose that the other eight parameters are discarded or irrelevant, which could mislead the agent into providing unnecessary input.

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 brief and to the point, with no unnecessary words. It consists of two sentences that directly convey the core functionality.

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 description lacks information about output format, error conditions, or the role of the many extraneous parameters. Given the confusing schema, the description is insufficient for an agent to use the tool 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?

The schema descriptions for parameters like ref, city, and feed are nonsensical in the context of the citation tool and appear to be copy-paste errors. Only the URL parameter's description aligns with the tool's purpose, but the misleading descriptions for others harm usability.

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 clearly states the tool returns host, scheme, and HTTP status for a URL, with a specific verb and object. However, it doesn't distinguish from sibling tools like fetch-status or normalize-url, which may overlap.

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 no guidance on when to use this tool over alternatives, nor does it clarify that only the URL parameter is relevant while others are ignored. This leaves the agent uncertain about parameter requirements.

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