List mailing lists

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered by structured data. The description's only added value is enumerating the fields returned per list, which helps the agent judge whether the call answers its question, but it says nothing about pagination, ordering, or result size.

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?

A single compact phrase with no wasted words, and the field list is front-loaded. It is a sentence fragment rather than a complete statement, which slightly weakens its standalone 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?

With no output schema, the description does the right thing by naming the returned fields, which is the key missing piece. However, it omits whether results are paginated or how many lists come back, which matters for an unfiltered enumeration call on an open-world dataset.

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?

The tool takes zero parameters, so there is no parameter semantics to document; the baseline for a 0-param tool applies. The description correctly implies the call returns everything without filtering, which matches the empty schema.

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 is a noun phrase ('All mailing lists with id, name, type, opt-in mode, tags, and subscriber counts') that implicitly states the resource, and the title supplies the verb. It loosely distinguishes this from the singular list_get, but never explicitly scopes itself against siblings like list_create or subscribers_search.

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?

There is no guidance on when to use this tool versus list_get or any sibling. An agent must infer from the plural name that this is the enumeration endpoint; no conditions, prerequisites, or alternatives are stated.

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