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

The readOnlyHint annotation already covers the safety profile. The description adds useful behavioral context by noting AND-combined filters and offset/limit paging with next_offset, but it does not discuss permissions, rate limits, or the returned record shape.

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 purpose, filter behavior, and paging. The list of useful fields and the trailing POST endpoint are somewhat implementation-focused, but they do not make it bloated.

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 search tool with a rich input schema, the description covers the essential query behavior: filtering, paging, and example fields. The lack of output schema is partly offset by the next_offset paging hint, though the returned record structure is not described.

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 parameter meanings are already well documented in the schema. The description reinforces AND filter behavior and paging with next_offset, and lists example lead fields, but it adds little beyond the structured 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 states a specific verb and resource, 'Search leads', and clarifies that leads are enquiries from portals, the website, and email. It does not explicitly distinguish this search tool from siblings such as rex_get_lead or rex_describe_search_fields, so it falls short of a 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?

Usage is implied by the search-oriented name and the mention of filter and paging mechanics. However, the description does not say when to use this tool instead of rex_get_lead, rex_search_contacts, or rex_describe_search_fields, and it gives no explicit exclusions.

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