check_candidatesFree. For each person (profile_url, profile_id, or full_name with current_employer), whether they are in the seen register and with which status, in input order.
| Name | Required | Description | Default |
|---|---|---|---|
| identities | Yes | People to check, in the order to return. |
| Name | Required | Description | Default |
|---|---|---|---|
| cost | No | ||
| data | No | ||
| has_more | No | ||
| next_cursor | No |
Changes observed during successful MCP inspections.
Input schema / properties / identities / items / properties / profile_id / descriptionPrevious value: -"Search id or the other member id. Either matches the same person."New value: +"Search id or the other profile id. Either matches the same person."Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real value: cost ("Free") and the guarantee that results come back "in input order," plus the fact that a status is returned per person.
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?
A single sentence with the cost cue front-loaded, followed immediately by the operation and its input/output contract. No filler.
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?
An output schema exists, so return format need not be explained, and the description still notes the returned status and ordering. What's missing is only minor: no note on behavior for unmatched people or rate/limit context beyond "Free."
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%, so the schema already documents all four identity fields and their matching rules. The description restates the identifier alternatives and implicitly notes max-of-one-person-per-entry, adding little beyond the structured schema — baseline 3 is right.
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?
Names a specific verb (check) and resource (the seen register), and spells out the identity forms accepted so an agent knows exactly what input qualifies. No sibling (billing, lists, guides, resolve_*) overlaps this register-lookup purpose, so it is unambiguously distinguishable.
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?
"Free" signals a zero-cost call an agent can use liberally, and the ordering contract implies batch-style usage. However, it never states when to reach for this tool versus not doing so, nor any prerequisites (e.g. registration expectations).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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