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

Annotations cover only readOnlyHint and openWorldHint, but the description adds substantial behavioral context: ~10-minute caching, per-IP rate limiting, retry-on-5xx guidance, and precise pagination semantics including the empty-items/has_more=false edge case. This is exactly the kind of operational detail annotations cannot express.

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 field list come first, then sibling routing, then pagination and operational notes. Every clause carries information an agent needs; no filler or restatement of the title.

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?

For a two-parameter list tool with an output schema, this is complete: it covers scope, routing, pagination mechanics, edge cases, caching, and rate limits. An agent has everything needed 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 100%, so the baseline is 3, but the description adds real value beyond the schema: it explains that next_offset should be passed back as offset, that offset is a raw row count advanced by limit, and that an out-of-range offset yields an empty items list. It does not, however, clarify why a raw row count differs from page index, which is the one subtle risk.

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 (enumerate) and resource (ESG reporting frameworks/standards), lists the concrete items returned (abbreviation, description, website), and explicitly names the sibling it is not (list_esg_pages with section='standards'). An agent can distinguish it from list_esg_resources or list_esg_pages without opening a 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?

Explicitly says when to use this tool ('to discover coverage') and when to use an alternative ('for the ESG Hub articles that explain a standard use list_esg_pages with section=standards'), even supplying the exact parameter value. Nothing is left to inference.

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