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

Annotations cover only read-only/open-world status; the description adds substantial behavior beyond them: title ordering, page mechanics (next_offset/limit/offset), empty-result semantics (empty list with has_more=false), ~5-minute caching, per-IP rate limiting, and 5xx retry guidance. This is well above the annotation baseline.

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, routing, pagination, and operational caveats are front-loaded in one dense paragraph. Every sentence carries information, though the semicolon-chained operational notes (caching, rate limits, retry) make it slightly heavy to parse.

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 an output schema present the description needn't detail return values, and it still clarifies the relevant fields (next_offset, has_more). Pagination, filtering constraints, empty-results, and failure/retry behavior are all covered, leaving nothing an agent needs to call it correctly.

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 already 100%, so the baseline is 3. The description still adds value: 'query' is an exact substring (not fuzzy), 'domain' must be a host from get_esg_metadata's domain list, 'limit' caps at 100, and 'offset' should be advanced by 'limit' using the returned next_offset.

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 ('Enumerate curated external ESG resources') and enumerates the sub-categories (standards bodies, regulators, tools, databases). It explicitly distinguishes itself from the sibling 'list_esg_pages' for ESG Hub's own articles, so an agent can route 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?

Gives the use case ('assemble authoritative references'), names the alternative (list_esg_pages for internal articles), and points to get_esg_metadata as the source of valid domain values. Conditions for correct invocation are all present.

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