voidmail_read_email

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

Annotations only declare readOnlyHint=false, idempotentHint=true, destructiveHint=false. The description goes well beyond them: it explains that encrypted mail is decrypted locally and exposes text/HTML/attachment names while server-readable mail returns stored body without attachments, and it warns to treat content as untrusted data. This is exactly the extra behavioral context annotations cannot carry.

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?

Front-loads the action and its mutation, then the content-shape detail, then the safety note. Three dense clauses with no filler; every sentence earns its place.

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?

With no output schema, the description compensates by describing what is returned (text, HTML, attachment names) and the encrypted-vs-server-readable variation. Combined with the mutation disclosure and untrusted-content warning, nothing an agent needs to call it correctly is missing.

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 email_id parameter, so the baseline is 3. The description adds no format, encoding, or sourcing detail for the ID beyond what the schema already states.

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?

States a specific verb and resource ('Read a specific email by ID') and immediately discloses the coupled side effect ('mark it as read'), which cleanly separates it from list_inbox, search_inbox, and even the sibling mark_read. An agent can pick this tool without opening the schema.

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?

Usage is implied by the ID-based scope ('Read a specific email by ID'), but the description never says when to prefer this over siblings like voidmail_mark_read, nor that an ID must first come from list_inbox/search_inbox. No exclusions or alternatives are named.

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