Web Fetch

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

Annotations already declare readOnlyHint and openWorldHint, so safety and network exposure are covered. The description adds that content comes back as cleaned Markdown rather than raw HTML, which is useful, but says nothing about fetch failures, JS-heavy pages, truncation defaults, or rate limits.

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?

Two tight sentences with zero filler; the capability statement is front-loaded ahead of the usage guidance. 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 an output schema present and 100% schema documentation, the description needn't explain return values or parameters. It covers purpose and routing adequately; only edge-case behavior (failures, truncation) is absent, which is minor given the structured data available.

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%, and both parameters (url, max_chars) are fully documented in the schema including the 0-means-no-truncation semantics. The description adds no parameter-level meaning beyond that, 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') plus the transformation performed ('return its main content as Markdown'), and scopes it to a single page. An agent can distinguish this from the sibling web_search without opening either schema.

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 two concrete triggers: when search snippets/summaries are insufficient, and when the user pasted a URL to read. The first implicitly points at the web_search sibling as the fallback, but there is no explicit when-not-to-use or named alternative tool.

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