Fetch a page

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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=true, idempotentHint=false). The description adds value beyond them by disclosing the failure surface: an explanatory error when the page is unreachable, blocked, or has no extractable content, and the shape of a successful return.

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?

Front-loaded with purpose, followed by usage and return/error behavior in three short paragraphs with no filler. Slightly more line-broken than needed, but 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?

For a read-only fetch tool with no output schema, the description covers return shape, error behavior, and usage context. It is nearly complete; only a note on truncation interaction with max_chars would close the remaining gap.

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 all three parameters are already documented, including url normalization and max_chars=0 semantics. The description adds nothing about max_chars or response_format, 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 and resource ('Fetch one web page') and names the exact return payload ('title plus the full text as Markdown') and the backing API. The word 'one' implicitly separates it from the sibling fetch_many.

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?

Gives a concrete trigger ('use it on a url returned by search when the summary is not enough, or on any URL the user provides'), which is clear when-to-use context tied to the search sibling. It never states when NOT to use it or explicitly contrasts with fetch_many, so it stops short of a 5.

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