read_email

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

No annotations exist, so description carries full burden. Discloses read-only nature, API key requirement, untrusted data safety warning, and hard-stops. Even explains behavior when key is missing (returns setup instructions). Exceptionally transparent.

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?

Description is moderately long but each sentence provides necessary information: purpose, mode, safety, requirements. Front-loads core action and mode. Could be slightly more concise but earns its length.

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?

Tool has no output schema, so description explains response contents (headers+textBody, safety block). Covers input, behavior, safety, and setup needs. Given simplicity of tool, description is thorough and leaves no major gaps.

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 67% (2 of 3 params described). Description adds value by specifying that 'id' should come from a search hit's messageId. For other params, description relies on schema. Adds moderate extra meaning.

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?

Clearly states it fetches one full email by id, specifying 'CONNECTED MODE' and linking to search's messageId. Verb 'fetch' plus resource 'email from RadMail inbox' is specific. Distinguishes from siblings via read-only nature.

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?

Explicitly says use after a search hit, mentions it's read-only (no sending/drafts), and requires RADMAIL_API_KEY. No explicit 'when not to use' but context is clear. Could add more guidance on alternatives among siblings.

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