List Correspondents

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds useful behavior: the meaning of `last_correspondence` (null when no documents) and that `ordering` accepts it. Still, it does not disclose return details beyond one field, and pagination behavior is left implicit.

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 short and front-loaded, with the core action stated first and one additional field-semantics sentence. Every sentence earns its place, and there is no boilerplate. The formatting with backticks is slightly awkward but does not hurt readability.

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 list endpoint, the main gap is the undocumented `name__icontains` filter, which an agent would need for name-based lookups, and the lack of allowed ordering fields beyond `last_correspondence`. The output schema and annotations reduce some burden, but the description does not equip an agent to use both the pagination and filtering parameters confidently.

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 must compensate, but it only clarifies `ordering` (as accepting `last_correspondence`). The non-obvious `name__icontains` filter is left unexplained, and `page`/`page_size` are only inferable by convention. This is insufficient compensation for four undocumented parameters.

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 states a specific verb and resource: 'List correspondents.' It is clearly distinct from singular siblings like get_correspondent and mutating ones like create_correspondent. However, it does not explicitly contrast with any sibling, so it stops short of 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?

No guidance is given on when to use this tool versus alternatives. The description implies usage through the verb 'List' but never states exclusions or references get_correspondent or list_documents. A tool that merely names its action without selection criteria provides no real usage direction.

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