list_rules

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

With no annotations, the description carries the transparency burden. It usefully discloses the return shape and the presence of a next_page_token, and mentions 'trimmed_rule.' However, it does not state whether the operation is read-only, how mailbox selection works, what include_raw does, or how pagination is intended to be used.

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 extremely concise and front-loaded: one clear purpose statement followed by a compact return-type snippet. Every element earns its place with no filler.

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?

The tool is simple, but without annotations, output schema, or parameter explanations, the agent is missing essential invocation details. The description covers what the tool does and roughly what it returns, but not how to use its options or when to prefer it over related tools.

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 explain the parameters, but it does not. 'mailbox' and 'include_raw' are left completely opaque, and even the return note about 'trimmed_rule' only weakly hints at what include_raw might control.

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 inbox mail rules.' It clearly distinguishes from sibling get_rule, which targets a single rule, and is not a mere restatement of the tool name.

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 about when to use list_rules instead of get_rule, search_messages, or other list tools. There is no mention of alternatives, exclusions, or conditions that would select this tool.

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