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

Annotations already provide readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds important behavioral context beyond annotations: SSRF-guarding, protocol restrictions, body size cap, robots-awareness, and plan-dependent robots acknowledgement behavior. It doesn't detail failure modes or redirect handling, but the disclosed traits exceed what annotations alone convey.

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 sentences front-load the core action and scope, then pack constraints into a compact, scannable list. Every clause earns its place with no filler or redundancy.

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 4-param read-only fetch tool with 100% schema coverage, the description is nearly complete. It covers constraints (SSRF, protocol, size, robots), parameters are fully described in schema, and the read-only safety profile comes from annotations. Missing details like redirect handling or response encoding are minor given the tool's simplicity and openWorldHint.

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%, with each parameter (url, timeout_ms, user_agent, acknowledge_robots) having a meaningful description. The tool description itself doesn't add param-level detail beyond the schema, but the schema already carries the full burden. 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?

The description states a specific verb (Fetch), resource (raw decoded HTML of a public web page), and explicit scope constraints (public, http(s) only, 10 MB cap, robots-aware). It distinguishes itself from web_scrape_page and web_extract_table by focusing on raw HTML retrieval versus structured extraction.

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 implies its use case: fetching raw HTML for further analysis, as opposed to web_scrape_page (which likely extracts structured content). It doesn't explicitly name alternatives or state when not to use it, but the constraint 'public web page' plus sibling names provide clear context. It lacks explicit routing guidance like 'use web_scrape_page for structured extraction'.

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