list_emails

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

Annotations already mark it readOnly and openWorld, so the safety profile is covered. The description adds the ordering guarantee ('newest first') and summarizes the filterable dimensions, but it does not disclose return shape, pagination defaults, or how filters combine. Given the annotations, this is adequate but not rich.

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, with the action and ordering front-loaded and the filter list in the second sentence. 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, filterable list endpoint, the description plus fully described schema covers what an agent needs: resource, ordering, available filters, and pagination parameters. No output schema exists, but the absence of a return-shape statement is not critical for a list tool with these annotations.

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?

All 7 parameters are documented in the schema (100% coverage), so the baseline is 3. The description merely recaps the filter categories already present in the schema without adding semantics such as format, defaults, or interaction between filters.

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 the specific verb 'List' and the resource 'messages of the CamelMailer server', then adds ordering ('newest first'). This makes it clearly a read-only listing tool and distinguishes it from single-item getters like get_email and from list_streams/list_campaigns by resource.

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?

It states the primary use case (listing messages) and enumerates the available filter dimensions, giving an agent clear context for when to call it. It does not, however, name any alternative tools or exclusion conditions, so it stops short of explicit when-not-to-use guidance.

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