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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld). The description adds genuinely new behavioral context: the cost model (free within the daily allowance, then $0.001 USDC per call via x402), which is decision-relevant for an agent and absent from structured fields. It doesn't describe pagination or error behavior, but the added cost disclosure is valuable.

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?

Two sentences, front-loaded with returned fields before the pricing note. No filler. The content sentence is a dense list, but every element earns its place.

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, return values need not be explained, and annotations carry the safety profile. The description covers scope, returned fields, and pricing, leaving little an agent needs missing, though explicit sibling routing would complete it.

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% and the single 'code' parameter is already documented with concrete examples (RVV, G82052). The description only reinforces the 'one ODS code' scope without adding format or syntax beyond the schema, so baseline 3 applies.

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?

The description gives a specific verb-less but concrete resource enumeration: name, status, address, phone/website, roles and relationships for one ODS code. An agent understands this is a single-entity lookup keyed by ODS code, distinct from the search sibling. It doesn't explicitly name which sibling to use instead, so it lands at 4 rather than 5.

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?

The phrase 'for one ODS code' implies this is the single-entity retrieval path versus nhs-organisations__search, but there is no explicit when-to-use/when-not guidance or named alternative. Usage is inferable but never stated.

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