epost_get_letter

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

No annotations are provided, so the description carries full burden. It does not disclose behavioral traits like whether the operation is read-only, requires authentication, or has any side effects. The description only states what it returns, not how it behaves.

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 (18 words) that efficiently communicates the core purpose. It earns its place with no superfluous information, though it could benefit from minor structuring (e.g., bullet points for included fields).

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?

Given the tool has only one parameter and no output schema, the description is minimally adequate. It covers what the tool returns but does not explain the output structure, error handling, or relationship to other tools in the e-post system. For a simple retrieval tool, it meets basic needs but lacks completeness.

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?

With 0% schema description coverage, the description should explain the parameter. It only says 'its id' without clarifying the format, source, or constraints of the letter_id. The schema lists it as a required string with no description, so the tool adds little semantic value.

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 that the tool retrieves one letter by its ID, specifying the included details (sender description, document types, dates, read status). This distinguishes it from siblings like epost_list_letters which lists multiple letters.

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?

No explicit guidance on when to use this tool versus alternatives. The description does not mention prerequisites, such as needing the letter_id from another tool, nor does it advise against using it for bulk operations. Siblings exist (e.g., epost_search, epost_list_letters) but no comparison is provided.

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