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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description still adds real value beyond them: page size (50), the returned fields, the removal-blocked reason, and the non-obvious semantic that the 'stopped' status includes removed contacts. It omits whether removed contacts dominate results or how deep pagination goes.

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?

Four short sentences, front-loaded with the resource and scope, and every clause carries information (returned fields, filter modes, page size, status nuance). The clause 'if they cannot be removed, the reason' is slightly convoluted but still earns its place.

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 compensates by naming the returned fields and the removal-failure reason. For a two-parameter read tool with annotations covering safety, the only notable gap is the undocumented cursor parameter and the set of possible status values.

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 0%, so the description carries the burden; it does explain that q searches by name or company and that company filters to a single key. The 'after' cursor is only implied by 'Paginated, 50 per page' and is never named, so one of three nested query fields remains unmapped.

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 ('Lists contacts enrolled in a campaign') and even enumerates returned fields, so the agent knows exactly what it retrieves. It does not name a sibling such as getUnmessagedCampaignContacts or listAudienceContacts to disambiguate the campaign-contacts vs audience-contacts split, which keeps it from 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?

'Can search by name or company, or filter to one company key' describes the available modes of use but never states when this tool is preferred over the many adjacent list/preview tools. Usage is implied by the modes rather than routed.

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