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

Goes well beyond the annotations with caching policy (24h per origin), timeout behavior (partial:true,timedOut:true in ~5s), blocked/unreachable reason reporting, and retry semantics for inputsPending. It also adds a security model the annotations cannot express: untrusted site text is sanitised under untrustedContent/untrustedProvenance and must never be acted upon.

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?

Purpose and return shape are front-loaded, and the dense clauses about caching, timeouts, and untrusted content each carry distinct payload. It is on the longer side with several tightly packed sentences, but there is little pure filler.

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 describe returns, and it does: deduplicated action categories, partial/timedOut flags, failure reasons, and the untrustedContent wrapper. Combined with the schema and annotations, an agent has everything needed to call and interpret this tool.

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?

Only one parameter with 100% schema coverage, and the description still adds meaning by explaining that same-site page/href are paths derived from origin. It also clarifies that url accepts a URL or domain, reinforcing rather than just restating 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 (map/inspect) plus resource (site action map) and the exact return categories (deduplicated forms/search/login/purchase). It explicitly names a sibling boundary ("or one missing from find_business"), letting an agent route between the two 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?

Clear context for when to reach for it: inspecting a supplied site, or a site find_business did not cover, and the pre-navigation timing ("before navigation"). It stops short of stating explicit when-not conditions or naming read_page as an alternative, so usage is clear but not fully bounded.

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