list_emails_all

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

With no annotations provided, the description carries full burden and adds valuable behavioral context: it warns about large result sets, specifies return format (array of objects with id, subject, from, date), sorting (newest-first), and how to use the id with fetch_email_content. This goes beyond basic listing to include practical usage details.

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 front-loaded with core purpose, followed by warnings and return details, all in three efficient sentences with zero waste. Each sentence adds critical information (scope, risk, output format, and usage guidance), making it appropriately sized and well-structured.

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?

Given no annotations and no output schema, the description compensates well by explaining return values and behavioral traits. It covers purpose, usage context, and output semantics adequately for a list tool, though it could mention pagination or limits for very large results to be fully complete.

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% for the single parameter 'mailbox', which is documented in the schema. The description does not add any parameter-specific information beyond what the schema provides, so it meets the baseline of 3 without compensating or detracting.

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 clearly states the verb 'List' and resource 'ALL emails in the mailbox', specifying scope 'no date filter'. It distinguishes from siblings like list_emails_24h, list_emails_7days, etc. which have date filters, making the purpose specific and differentiated.

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?

The description provides clear context with 'no date filter' and a warning about potentially large results, implying when to use it (for unfiltered listing). However, it does not explicitly state when not to use it or name alternatives, though siblings suggest date-filtered options exist.

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