Web reader: read

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

Annotations already declare readOnlyHint and openWorldHint, so the description's added value is the failure modes it discloses: empty results behind logins/paywalls and truncation on long pages. That is real behavioral context beyond the structured fields, though it omits rate limits or JS-rendering behavior.

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 compact sentences: purpose first, routing second, limitations last. No filler and every sentence carries distinct information.

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 one-parameter read tool, the description covers intent, return format (Markdown), sibling routing, and known failure modes, while annotations carry the safety profile. Nothing needed to invoke it correctly is missing despite there being no output schema.

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 coverage is 100% and the single 'url' parameter is fully documented in the schema, including the http(s):// pattern. The description's phrase 'any public web page' adds only marginal meaning, so the baseline 3 applies.

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?

States a specific verb (Fetch), resource (any public web page), and the return transformation (main content as Markdown, nav/ads stripped). This makes it clearly distinct from every sibling, which are all domain-specific lookup 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?

Explicitly frames itself as a fallback and names the alternatives ('prefer wikipedia_summary, github_repo etc. when they fit'), which directly routes the agent among siblings. The when-to-use condition is stated, not implied.

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