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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is fully covered structurally. The description adds nothing on top: no pagination behavior, no filtering semantics, no indication of result size or shape for a free-form 'query' object. It repeats 'GET /api/contacts' twice, which conveys no additional information.

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 but wastes its entire length on a verbatim duplicate of the endpoint path ('GET /api/contacts. GET /api/contacts.'). There is no front-loaded statement of purpose, so the brevity reflects under-specification rather than economy.

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 listing endpoint with a nested free-form query object, no output schema, and zero documented parameters, the description should at minimum say what a contact is, what the query object accepts, and how results are ordered or paginated. It supplies none of that, offering only a reference to describe_operation.

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 0% across two parameters, and the 'query' object is a free-form additionalProperties bag while 'params' is an empty, closed schema — exactly the case where the description must compensate. Instead it only says describe_operation provides native request schemas, which outsources the explanation rather than providing it; the agent learns nothing about what keys go in 'query'.

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 is essentially a restatement of the endpoint path and title ('GET /api/contacts') rather than an explanation of what contacts are or what listing them returns. It does convey that this is a read of the contacts collection, but that is inferred from the raw route rather than stated, and it does nothing to distinguish it from siblings like get_contacts_by_id, get_counterparty_contacts, or get_sites_by_siteId_contacts.

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?

No when-to-use guidance is given; the only actionable statement is a pointer to describe_operation for native request schemas. There is no mention of the related sibling tools (single-contact lookup, counterparty contacts, custom field definitions) or of when this collection endpoint is preferable to them.

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