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

readOnlyHint=true already tells the agent this is a safe, non-mutating read. The description adds only the endpoint mapping (GET /contacts); it doesn't disclose pagination behavior, result ordering, or what happens when term matches nothing, so added value over annotations is modest.

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, purpose front-loaded before the endpoint note; nothing is wasted. It is efficient though not especially information-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/search tool with fully documented parameters and no output schema, the description covers what an agent needs to call it correctly. The missing piece is what the return payload looks like and how paging results behave, which is minor here.

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 page, term, and include_last_interaction are already documented in the schema. The description restates the match fields for term but adds no syntax, format, or behavior beyond that, making the baseline 3 appropriate.

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?

States a specific verb (list/search) and resource (contacts) plus the searchable fields, so the agent knows exactly what the tool does. It doesn't contrast itself with siblings like trengo_get_contact or trengo_list_contact_groups, so it stops 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: use with no term to list, with a term to search. There is no explicit guidance on when to prefer this over trengo_get_contact (single contact) or other list_* siblings, and no prerequisites or exclusions are mentioned.

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