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

readOnlyHint=true already establishes the safe-read profile, so the description's main added value is confirming this is a scoped GET on /crm_persons/. It says nothing about pagination limits, whether the list is filtered to the authenticated client, or what a contact record contains — modest value beyond the annotation.

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 terse sentences, front-loaded with the resource and audience, with zero filler. The endpoint fragment is mildly redundant but gives useful API grounding; nothing is buried or over-explained.

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?

There is no output schema, and the description does not characterize the returned contact records at all (fields, ordering default, or that filtering supports custom fields). For a nested-filter list tool this leaves a gap, although the readOnly annotation and full param coverage keep it close to adequate.

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%: page, page_size, sort and filter (including the nested value/comparison shape) are all documented with examples in the schema. The description adds no parameter guidance, so the baseline 3 applies — the schema does all the work here.

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 and resource ('List contact people (crm_persons) of client companies') and pins the API scope as crm_person with the underlying endpoint. This separates it from traffit_get_contact (single record) and traffit_list_clients, though the description never names those siblings 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 phrase 'of client companies' implies the use case (browsing contacts attached to clients), but there is no explicit statement of when to use this versus traffit_list_clients or traffit_get_contact, and no exclusions or prerequisites. Usage must be inferred from the scope line.

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