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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'read-only batch lookup'. It adds valuable behavioral context: the filter matches 'ANY' selector and returns only 'approved rows', and the scope is the 'platform-wide canonical vendor registry'. This goes beyond the annotations, though it does not mention pagination behavior or potential truncation.

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?

The description is three sentences, front-loaded with the core purpose, and every sentence adds information. It avoids redundancy with the schema and annotations, making it both concise and structurally effective.

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?

Given the complexity (nested filter, pagination) and the presence of an output schema, the description covers the essential behavioral aspects: read-only, global scope, batch filter semantics, and OR matching. It does not explain pagination, which might be expected for a list tool, but the use case ('whole batch in one RPC') suggests it may return all matches. Overall, it is complete enough for an agent to use effectively, with minor gaps around pagination.

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 0%, so the description must compensate. It explains the filter's key semantics: 'accepts a list of provider stable IDs and/or aliases', which covers the filter object's properties. However, it provides no additional meaning for pageSize or pageToken, leaving those parameters entirely to the schema. The description adds value for the complex filter but does not fully compensate for all parameters.

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 clearly states the tool performs a 'read-only batch lookup' against the 'platform-wide canonical vendor registry', which distinctly differentiates it from sibling tools like counterparty_get_counterparty (singular) and counterparty_get_list_counterparties (non-global). It also specifies the OR-matching semantics ('matching ANY selector'), making the purpose unambiguous.

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 description provides a concrete use case: 'Used by the cheap-resolve worker to short-circuit LLM enrichment for a whole batch in one RPC.' This implies when to use the tool, but it does not explicitly name alternatives or state when not to use it. The batch and platform-wide context is clear, but explicit exclusion guidance is absent.

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