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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety and external-network profile is covered structurally. The description adds the scope of what is extracted, but says nothing about how the page is fetched/rendered, what happens on unsupported or JS-heavy pages, or whether output is truncated.

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?

One sentence, verb-first and front-loaded, with the enumeration earning its length by telling the agent what comes back. No filler, though the list is long enough that the core action could be read faster if trimmed.

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?

Simple two-parameter read tool with strong annotation coverage; since there is no output schema, the enumerated artifact list usefully substitutes for describing the return value. Only failure/error behavior is unaddressed, which is a minor gap at this complexity.

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%, so the baseline would be 3; the description's 'from any URL' wording reinforces that url is a fetch target rather than a local path, adding slight value. It says nothing extra about api_key's rate-limit effect, which the schema already covers adequately.

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 (Extract) and resource (a standardized DESIGN.md) and enumerates the extracted artifacts — CSS custom properties, typography hierarchy, button/card specs, palettes, layout guidelines. That enumeration implicitly distinguishes it from siblings like generate_content_md or generate_links_md, but no sibling is named explicitly.

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?

Usage is only implied: fetch a URL and get design tokens out. There is no explicit statement of when to choose this over url_to_markdown or the other generate_* siblings, and no prerequisites or exclusions are given.

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