io_list_mail

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

The readOnlyHint annotation already tells the agent this is a safe read, so the description only needs to add on top of that. It contributes the result scope (packages and letters) and notes filtering/pagination exist, but says nothing about sort defaults, page-size behavior, or what a list response looks like — modest added value over 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?

Two short sentences, zero filler, with the tool's core action front-loaded immediately. Nothing here would need to be cut.

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 tool with a fully documented 11-parameter schema, the essentials are covered, but with no output schema the description could say more about the shape of the returned list (fields, totals, page metadata). It is adequate but leaves real gaps.

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% across all 11 parameters, including detailed docs for view, limit, and the date/search filters, so the schema carries the full burden. The description adds no parameter syntax or constraint beyond what the schema already states, which is the baseline-3 case.

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?

States a specific verb and resource ('List iOffice mail items') and adds scope by naming the two item types it returns (packages and letters). It does not, however, differentiate itself from siblings such as io_get_mail or io_deliver_mail, so an agent gets no explicit routing signal beyond the list verb.

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?

'Supports filtering and pagination' describes a capability, not when to choose this tool over io_get_mail or how to bound a query. There is no statement of when-not to use it, no prerequisite, and no named alternative.

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