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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds meaningful behavioral context: criteria combine with AND, results are paged, next_offset indicates continuation, and field discovery requires rex_describe_search_fields. It does not describe auth, rate limits, or detailed return shape, but with the read-only annotation present the added context is solid.

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, front-loaded with the tool's purpose, and moves efficiently through filtering semantics, paging, useful fields, field discovery, and the endpoint. No sentence is wasted.

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 full schema coverage and annotations, the description covers the essential purpose, filtering, paging, and field-discovery workflow. It does not explain the response item shape beyond paging, and no output schema exists, but the core calling guidance is complete enough.

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 limit, offset, criteria, order_by, and search_state thoroughly. The description mostly restates schema-level semantics such as AND-combined filters and offset/limit paging; its main extra value is naming useful fields and pointing to rex_describe_search_fields, which the schema also does.

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 gives a specific verb and resource: 'Search notes recorded against contacts and properties.' This clearly distinguishes it from note-fetching and note-creation tools, and from the many sibling search tools that target other resources.

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 explains the mechanism for filtering and paging, names rex_describe_search_fields for discovering related contact and property fields, and gives useful field examples. It does not explicitly say when to use this instead of rex_get_note for a known note or other sibling searches, but the resource scope is clear.

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