search_mail

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, yet the description still adds real behavior: ascending UID ordering, inclusive/exclusive date boundaries, IMAP internal-date basis, and the persisted-snapshot resume semantics. These are non-obvious traits an agent could not infer from the annotations or schema.

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?

It is a single dense, front-loaded block with no filler sentences; every clause carries information. The telegraphic, fragmentary style slightly hurts readability, which keeps it from a 5.

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 7-parameter, 0%-schema-coverage search tool with no output schema, the description never mentions the core filtering capability (folder, sender, subject) or the limit parameter. It gives strong date/cursor semantics but leaves the tool's primary use case and half its parameters unexplained.

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 coverage is 0% across 7 parameters, so the description must compensate. It does so well for since/before (format and inclusive/exclusive semantics) and cursor (resume overrides other filters), but folder, sender, subject, and limit are entirely undocumented in both schema and description, leaving most filtering parameters opaque.

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 name search_mail supplies the verb+resource, but the description opens with the cryptic 'Snapshot ascending UIDs' and never says it searches/filters mail. It conveys ordering and cursor behavior rather than a clear statement of what the tool returns, and it does not distinguish itself from read_mail or check_incremental. Purpose is only implied, not stated.

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 when-to-use guidance and no reference to alternatives like read_mail or list_folders. The only conditional guidance is internal cursor-resume behavior ('other filters are ignored on resume'), which is about mechanics, not about when to pick this tool over its siblings.

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