List correspondents

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

Annotations already cover the read-only, idempotent, open-world, and non-destructive aspects, so the description doesn't need to repeat those. It adds useful behavioral context by defining the domain concept and stating the exact return shape (id, name, document_count). This goes beyond the schema and annotations without contradicting them.

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?

Three short sentences each carry distinct value: the action, the domain clarification plus return fields, and the usage guidance. The most important information is front-loaded ('List correspondents'), and there is no filler or 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 read-only list endpoint with no required parameters and a fully documented schema, the description is largely complete: it states the purpose, the meaning of a correspondent, the return fields, and when to call it. It doesn't explicitly mention pagination behavior in prose, but the schema already documents page/page_size, and the annotations cover safety, so the remaining gap is minor.

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 the input schema already documents all five parameters, including filters, pagination, ordering, and the full flag. The description adds no parameter-specific meaning beyond that, so the baseline 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 a specific verb+resource pair ('List correspondents') and clarifies exactly what a correspondent is ('the sender or counterparty a document came from'). It also specifies the return fields (id, name, document_count), which makes the tool's purpose and scope unambiguous and distinguishes it from sibling tools like get_correspondent or create_correspondent.

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 explicit situational guidance: 'Call this before creating anything — reusing an existing correspondent is almost always correct.' This tells an agent when to use the tool and effectively steers it away from create_correspondent unless necessary, which is exactly the kind of alternative-routing the dimension asks for.

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