list_senders

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

With no annotations provided, the description carries full burden. It compensates well by documenting the return structure ('A dict with 'data' (list of senders with id, name, from_email, reply_to)'), which provides crucial behavioral context. It does not, however, disclose rate limits or auth requirements.

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 contains three efficient statements: purpose definition, usage context, and return structure. Every sentence earns its place. The content is front-loaded with the primary action, followed by usage guidance and return documentation.

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 zero-parameter tool without annotations or formal output schema, the description is complete. It documents the output structure inline (dict with data array and specific fields), which compensates for the missing output schema. No additional behavioral details are critical for this read-only listing operation.

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 contains zero parameters, which establishes a baseline of 4 per calibration guidelines. With no parameters present, there is no semantic information required beyond the schema itself.

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 opens with 'List all configured senders' - a specific verb (List) plus resource (senders). It distinguishes from siblings (list_campaigns, list_contacts, etc.) by identifying the specific entity type and linking it to campaign creation workflows.

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 phrase 'Use sender IDs when creating campaigns' provides clear contextual guidance linking this tool to the create_campaign sibling. However, it lacks explicit 'when not to use' guidance or mention of alternatives for other use cases.

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