Search emails

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

Discloses ordering (newest first), limit behavior, and field search semantics. Complements annotations (readOnlyHint, idempotentHint) with actionable 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?

Three sentences, each packed with essential information. No redundancy or wasted words. Front-loaded with main purpose.

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?

Covers sorting, default filter, filtering dimensions, and result count. Output schema exists so return format is external. Thorough for a search tool.

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?

Adds meaning to key parameters like 'fields' (search anywhere vs specific), 'limit', 'since'/'before', and 'unseen_only'. Explains behavior beyond schema descriptions; 70% schema coverage is complemented.

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?

Description clearly states it keyword-searches emails, with filtering options. Distinguishes from sibling 'proton_list_emails' by emphasizing keyword 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?

Provides clear context: broad search via 'text', restrict to subject/from/to/body, combine with date range and unseen flag. Lacks explicit when-not-to-use or alternatives, but sufficient.

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