fastmail_get_email

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

The verb 'Get' implies a read-only retrieval, which is useful but minimally disclosed. With no annotations provided, the description carries the full burden for behavioral transparency; it does not explicitly state that the email is not modified, not marked as read, or that no side effects occur.

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 a single concise sentence with no filler. It front-loads the action and resource, and every word earns its place for a tool of this simplicity.

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 one-parameter retrieval tool, the description is adequately complete: it names the input (email ID) and the general outcome (detailed information). The lack of an output schema makes the exact return fields unspecified, but this does not block correct invocation for a simple get-by-ID operation.

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 100% for the single parameter, so the schema already documents emailId sufficiently. The description only reinforces 'by its ID' without adding format, source, or usage nuance beyond what the schema provides.

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 action ('Get detailed information') and the resource ('specific email') identified by ID. It is distinguishable from list_emails because it targets a single email, but it does not explicitly name or contrast sibling alternatives, and 'detailed information' is somewhat vague about what fields are returned.

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 phrase 'by its ID' implicitly communicates a prerequisite: the caller must already have an email ID. However, the description does not state when to prefer this over list_emails or other siblings, nor does it provide any exclusion criteria.

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