imap_get_email

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

With no annotations provided, the description carries the full behavioral burden and meets it: it discloses the default output behavior (clean Markdown in markdownContent), the intentional safety boundary (raw HTML is omitted 'so it never crosses the boundary'), the truncation guardrail (maxContentLength protects the context window), and what the tool deliberately does not do (attachment bytes). These are precisely the behavioral traits an agent needs to trust the tool's output.

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?

Five sentences, each earning its place: core purpose, default behavior and format variants, workflow prerequisite, truncation guidance, and sibling routing. The most decision-critical information (what it reads, default format) is front-loaded, and there is zero filler or repetition.

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 9-parameter tool with no output schema and no annotations, the description covers a great deal: return fields, format semantics, truncation, workflow, and alternatives. The remaining gap is that IMAP UIDs are folder-scoped, and with folder defaulting to INBOX, an agent could fetch from the wrong folder after a search in another folder — a subtle correctness point the description leaves to schema inference.

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%, so the schema already documents every parameter, warranting a baseline of 3. The description adds genuine value beyond the schema: it explains the rationale for maxContentLength ('protect the context window — raise it for long messages') and ties uid to the output of sibling tools. Some bodyFormat detail is restated from the schema rather than extended, which keeps this from a 5.

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 names a specific verb and resource — "Read the FULL content of a single email by its UID" — and enumerates the full scope of what is returned (body, sender/recipients, date, attachment list, optional raw headers, text-attachment previews). It naturally distinguishes itself from siblings like imap_search_emails and imap_download_attachment, and the contrast with imap_get_latest_emails ('Use after imap_get_latest_emails gives you a uid') clarifies that the sibling only produces UIDs, not content.

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 prerequisite is explicit: 'Use after imap_search_emails or imap_get_latest_emails gives you a uid.' The exclusion is also explicit: 'To fetch attachment bytes, use imap_download_attachment.' This is textbook routing — the agent knows exactly when to invoke this tool and when to pick a sibling, with nothing left to inference.

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