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

No annotations are provided, so the description carries the full behavioral burden, and it adds essentially nothing: no statement about pagination defaults, result size, permissions, or ordering. The only operational detail (limit/offset) lives in the schema, not the description, leaving the tool's runtime behavior undisclosed.

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?

Two short sentences, with the capability statement front-loaded ahead of the usage hint, and no filler beyond a mild 'in the system'. It is appropriately sized for a simple list tool, though it is thin rather than dense.

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 list tool with fully documented parameters and no output schema, the description covers the essentials of what it returns conceptually. It omits pagination behavior, default ordering, and any differentiation from sibling list endpoints, leaving gaps an agent would need to fill by trial.

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 id, first, query, and offset, putting this at the baseline. The description adds no syntax or format detail beyond the schema, and its mention of filtering 'by ... company' is not reflected in the query parameter description ('name or email'), a minor inconsistency rather than an enrichment.

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 names a specific verb and resource ('Lists and filters contacts') and even clarifies the entity's real-world meaning ('buyers or suppliers'), so an agent knows the domain. It does not, however, distinguish itself from the closely named sibling listContactLabelValues, which an agent could easily confuse with contact listing.

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 an implied use case ('find specific users ... by their name, email, or company'), which maps onto the query parameter, so there is some when-to-use guidance. But it names no alternatives or exclusions, and with a sibling like listContactLabelValues in the set, the boundaries of this tool versus related list operations remain unstated.

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