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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds important non-obvious behavior: it does not execute JavaScript and only works on server-rendered responses. It could mention failure modes or rate limits, but for a read-only fetch tool the critical limitation is disclosed.

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 sentences with no filler: the core purpose is front-loaded, the limitation and alternatives follow immediately, and the example is compact. Every sentence earns its place.

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?

With a single simple parameter, rich annotations, and an output schema present, the description covers what is needed: purpose, usage timing, limitations, and alternatives. No critical gap remains for an agent to select and call this 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?

Schema description coverage is 100%, so the schema already documents the url parameter. The description adds the 'public URL' constraint and provides a concrete example, which is helpful but not a substantial expansion of the parameter's meaning.

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 specific verb and resource ('Fetch a public URL') and the concrete output ('clean LLM-ready Markdown from the server-rendered response'). It also distinguishes itself from siblings by explicitly noting it does not execute browser JavaScript, which differentiates it from web_search and related tools.

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 usage context: use it after web_search to read a reachable public source or to ingest a static page for analysis. It also names alternatives and when to prefer them, saying for SPA or empty-text pages to use web_search, a browser, or the site's API.

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