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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds the HTTP endpoint and the shape of returned fields, but says nothing about pagination behavior, result caps, or empty-result handling beyond what the schema states.

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 compact sentences: the first front-loads what the tool returns, the second covers filtering, with the endpoint as a trailing tag. Nothing is redundant or buried.

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 an 8-parameter read-only list tool with full schema coverage and annotations, the description supplies the essential missing pieces: what fields come back and which filters exist. Only the pagination workflow (limit/offset/next_offset) is left entirely to the schema, which is acceptable but slightly incomplete.

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 every parameter is already documented, including limit/offset semantics and the status enum. The description only restates filter dimensions and adds the nuance of 'exact email', which is marginal added value over the schema.

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 contacts') and enumerates the returned fields and the filterable dimensions, plus the underlying endpoint GET /contacts. It is clearly distinguishable from icontact_get_contact, though it never names 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 filter sentence implies usage scenarios (by status, exact email, name, list membership), but there is no explicit when-to-use/when-not guidance or routing to alternatives such as icontact_get_contact for single-record lookup. Usage is inferable rather than stated.

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