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

Beyond the annotations readOnlyHint=true and idempotentHint=true, the description discloses critical behavioral limitations: no browser JavaScript execution, server-rendered response only, and public URL scope. These traits materially affect invocation expectations and are not present in the annotations.

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 purposeful sentences plus one example, with the core action and key limitation front-loaded. No filler or redundant restatement of the schema or annotations; every sentence contributes to correct usage.

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 tool is simple with one parameter, an output schema, and strong annotations. The description covers what it does, its limitations, when to use it, and alternatives, leaving no material gap for an agent to select and invoke it 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 documents the single url parameter, but the description adds meaning by specifying 'public URL' and providing a concrete example call. This extra context helps an agent understand the parameter's expected format and access requirements beyond the terse schema 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 clearly states the tool fetches a public URL and returns clean LLM-ready Markdown, distinguishing it from web_search and other siblings by explicitly noting it does not execute JavaScript. The title and description align on a specific verb, resource, and output format.

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 gives explicit when-to-use guidance: after web_search to read a reachable public source or to ingest a static page. It also states when not to use it (SPA or empty-text pages) and names alternatives (web_search, a browser, or the site's API), which fully resolves tool-selection ambiguity.

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