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

Annotations already declare readOnlyHint/idempotent, so the description correctly spends its words on what annotations cannot say: favicon_url is the RESOLVED value a publish would actually ship, including brand-kit inheritance, and a crawler absent from ai_crawlers/search_crawlers has never been decided and is allowed by default. Those are exactly the non-obvious semantics an agent would otherwise misread.

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 what is read, then the two caveats that matter (resolved favicon, default-allow crawlers). Dense but every clause carries information; the 'baked into every published page's head / served at /robots.txt' clause is the only slightly padded part.

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?

No output schema exists, so the description must carry the return shape — and it does, naming the fields and clarifying the two values most likely to be misread (resolved favicon_url, absent-crawler default). Nothing needed to call or interpret this tool is missing.

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 both parameters (site_id, user_goal) are already documented in the schema; baseline is 3. The description implies the scope of site_id ('every site-level setting') but adds no syntax or format detail and never mentions user_goal, so it does not exceed the schema.

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?

Specific verb ('Read') plus an explicit enumeration of every setting returned: default title, meta description, Open Graph image, favicon, crawler policy, llms.txt, custom robots.txt. It also scopes the tool negatively ('not code'), which sharply separates it from design/source-reading siblings like read_design or get_site_brand.

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 clear usage direction: 'read them here rather than looking for them in the design source.' That steers the agent away from the wrong place, but it never names the mutation counterpart (update_site_settings) or says when an agent should prefer get_site / get_site_brand instead, so the routing is context-level rather than exhaustive.

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