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

The annotations already cover read-only and non-destructive behavior. The description adds meaningful extra context: the operation is free, requires read scope, and falls back to label-based similarity with a note when no embedding exists.

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 short and front-loads the core purpose. The clause 'basis embedding, or labels with a note...' is slightly awkward but still compact and informative.

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 rich schema, output schema, and annotations, the description is mostly complete for correct invocation. It covers prerequisites and fallback behavior, with only minor gaps around sibling differentiation and parameter details.

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 schema already documents anchor, limit, and scope. The description reinforces that the anchor is one person and explains the embedding/label basis, but adds little about limit or scope beyond the schema.

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 that this finds people similar to one person, with shared niches/organizations and reasons. It is specific about the resource, but does not explicitly differentiate itself from sibling identity tools such as identity_search or identity_people.

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?

It gives useful usage context: the read scope is required and identity_expand with labels should be run first if the person lacks an embedding. These are explicit prerequisites and an alternative path, though it does not compare against sibling search/listing tools.

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