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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds only the backing endpoint ("Trengo: GET /contacts"), which is marginal; it says nothing about pagination flow or result volume beyond what the schema's page param implies.

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?

One short sentence covering both modes, front-loaded with the primary action. Nothing extraneous; the endpoint note is a single compact clause.

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 three-param, read-only list tool with a fully documented schema and no output schema, the description is adequate but thin. It omits any hint of result shape (e.g. that include_last_interaction enriches each contact) or pagination expectations.

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 fully documented in the schema. The description's mention of matching on name, email, and phone merely restates the term parameter and adds no syntax or format detail.

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) and resource (contacts), plus the searchable fields (name, email, phone). It is distinguishable from trengo_get_contact by being plural/list-oriented, though it never names that sibling explicitly.

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?

The two modes (list vs search by name/email/phone) are implied by the single sentence, so an agent can infer that supplying a term triggers search. There is no explicit statement of when to prefer this over trengo_get_contact or how it relates to other list tools.

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