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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), and the description adds real substance: what signals are extracted (SBTi, ISO 14001, B Corp, reports), what site-level measurements are taken (green hosting, carbon.txt, page weight, CO2 per view), and the regulatory basis with an effective date. It stops short of disclosing scan depth limits (e.g., JS-rendered pages, crawl scope, caching) — a notable gap for a web-reading tool — and the 'read a website' framing sits somewhat uneasily with openWorldHint=false, though this does not rise to a direct contradiction.

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 front-loaded sentence that opens with the action and resource before layering on legal frameworks and measurement details. It is dense with parentheticals but every clause carries distinct information, with no filler or restatement of the tool name.

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 no output schema, the description usefully sketches the three result categories an agent should expect, which is the main thing it must supply. For a read-only, single-parameter tool this is close to complete; only the response shape and scan-coverage limits are left implicit.

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% for the single parameter ('Domain, e.g. example.com'), so the schema carries the semantics and baseline 3 applies. The description adds only the implicit notion that the domain is a company website; it does not clarify whether to pass a bare domain vs URL, or how subdomains/paths are handled.

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 ('Read a company website for environmental claims and greenwashing risk') and names the exact regulatory lenses (EU Directive 2024/825, UK CMA Green Claims Code) plus the three output classes: claims, evidence/credentials, and site footprint. No sibling tool (cra_disclosure_scan, battery_passport_check, etc.) overlaps this scope, so an agent can select it unambiguously.

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 implied by the regulatory framing and the single required domain argument, so the agent can infer it is for greenwashing/sustainability due-diligence on a company site. However, there is no explicit when-to-use/when-not-to-use statement, no mention of prerequisites (e.g., public site accessibility), and no routing to any alternative tool for adjacent regulatory scans.

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