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

readOnlyHint=true in annotations already establishes this as a safe read. The description adds useful context beyond that: the underlying API endpoint and the return envelope ({ meta, response }). It does not, however, describe pagination behavior, default ordering, or rate limits, so it goes modestly beyond annotations.

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?

Three terse sentences, front-loaded with what the tool is before the endpoint, supported params, and return shape. Every clause earns its place with no filler.

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?

With no output schema, the description compensates by stating the return shape ({ meta, response }), and parameters are fully documented in the schema. It is nearly complete for a read-only list tool, though it omits discussion of pagination limits or total counts in the meta.

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 each parameter is already documented in detail with examples. The description only restates the parameter names (_page/_limit/_fields/_filters/_search) without adding syntax or format meaning, so the baseline of 3 applies.

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'), and parenthetically disambiguates the resource as 'people at companies', which separates it from list_companies. It also maps to the concrete Accelo endpoint. It does not explicitly name sibling tools, but the resource clarification is enough to distinguish it.

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 description offers no when-to-use guidance or alternatives — it never says when to prefer list_contacts over get_contact, list_companies, or list_prospects, nor mentions prerequisites. It only enumerates supported query parameters, which is capability, not usage guidance.

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