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

Annotations only declare readOnlyHint=true, so the description carries the interesting behavioral load and does so: max 200 results, phone numbers are normalized for lookup but returned truncated to the last 4 digits with an instruction not to echo full numbers, and note fields drop phone/email. It does not describe ordering, pagination, or what the response envelope looks like.

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?

Front-loaded with the login prerequisite, then filters, then the result-handling caution, then the follow-up tool calls. Every clause carries information; nothing is redundant with the schema.

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 read-only 4-parameter listing tool with no output schema, this covers prerequisite, filtering, result cap, privacy masking, and next-step tools. Only result ordering/pagination and the meaning of the source enum are missing.

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 0%, but the description compensates well: q is explained as a normalized phone lookup with masked output, archived=true selects the archive, the 200 ceiling is restated, and source is named as a filter dimension. The PLATFORM/PRIVATE enum values themselves are never explained.

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 and resource (list the caller's own lead pool) and states the scope filters (source / q / archived) plus a hard cap of 200. It does not explicitly contrast itself with nearby siblings such as collect_broker_leads or list_broker_fresh_joiners, so the differentiation from those is left to the agent.

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?

Gives clear workflow context: sign-in is required, archived leads are reached via archived=true rather than by a separate tool, and after verifying leads the agent should call scan_broker_matches(leadIds) or import_broker_leads for new data. No explicit 'do not use this when…' exclusion is stated.

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