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

The description discloses behavior beyond the annotations: it validates the key against the Apollo API, stores the integration, and notably reveals that a failed validation still creates an integrationId. This partial-failure behavior is valuable and not contradicted by the 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?

Four sentences, each earning its place: the main action, validation behavior, return semantics, and a next-step pointer. The description is front-loaded with the core purpose and avoids redundancy.

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 simple two-parameter connector with no output schema, the description adequately explains the operation, validation outcome, partial-failure behavior, and what to do next. It provides enough information for an agent to select and invoke the tool correctly without ambiguity.

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?

The description clarifies that apiKey is the Apollo API key and that it is validated against the Apollo API, adding meaning beyond the schema's type and minLength. The workspaceId parameter is already well-described in the schema as defaulting to the bound workspace, but the description does not add further context for it.

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?

The description clearly states the action: connect an Apollo.io account by providing an API key, then validates and stores the integration. It is specifically distinguished from sibling connect tools like campaignstack_connect_hubspot and campaignstack_connect_instantly by naming Apollo.io 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 description gives clear context for using the tool: connect an Apollo.io account with an API key. It also provides a helpful follow-up step, 'Use campaignstack_list_apollo_sources after connecting to browse available contact lists.' However, it does not explicitly explain when not to use it or how it compares to other connection tools.

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