Get Eligible Contacts

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

The annotation already marks the tool as read-only. The description adds behavioral context by mentioning that it respects dedup and mutual contact rules, which is beyond what annotations provide. It does not disclose error conditions or side effects, but the added detail is valuable.

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?

The description is a single sentence that is front-loaded with the verb and object. It contains no extraneous information and is maximally concise while conveying the essential purpose and constraints.

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?

Given that the tool has one parameter with full schema coverage and no output schema, the description fully explains what the tool does, what input it expects, and the behavioral rules. It is complete for the tool's simplicity.

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 input schema has 100% coverage, with the single parameter 'id' described as 'Campaign ID'. The description does not add any additional meaning or constraints to this parameter beyond what the schema already provides. Baseline score of 3 is appropriate.

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 uses the verb 'Get' and specifies the resource 'contacts eligible for receiving a campaign message', including constraints like dedup and mutual contact rules. This clearly distinguishes it from other contact retrieval tools such as list_contacts or search_contacts, which are general-purpose.

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 implies the tool is for obtaining eligible contacts for campaign messaging, but it does not explicitly state when to use it versus alternatives or provide any exclusions. Usage is clear from context, but no explicit guidance is given.

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