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

With readOnlyHint=true already declaring the safety profile, the description adds the returned content shape, including the 'latest import operation', which is genuinely useful context. It does not disclose auth requirements, rate limits, or the effect of the with_statistics flag, so it stays at an adequate level.

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?

Front-loaded single sentence listing the payload contents, with the REST endpoint appended for mapping context. Slightly more than strictly required, but every element is short and no sentence is wasted.

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 simple read tool with no output schema, the description compensates by enumerating the returned fields, which is exactly what an agent needs. The only gap is not explaining what with_statistics changes in the payload.

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% with only two parameters, so the schema already documents mailing_list_id and with_statistics (including its default). The description alludes to member counts/statistics but adds no syntax or behavioral detail beyond the schema, making baseline 3 correct.

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 ('Get one mailing list') and enumerates exactly what the response contains: name, member counts, status, custom field definitions, preferences, latest import operation. The singular 'one mailing list' clearly differentiates it from the sibling moosend_list_mailing_lists.

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?

Usage is only implied: an agent can infer you call this when you need details for a single list. No explicit when-to-use condition, prerequisites, or named alternative (e.g., moosend_list_mailing_lists for enumeration) is given, so guidance is minimal rather than absent.

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