Mailtext lesen

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

No annotations are provided, so the description carries the full burden. It discloses that it returns 'der ersten passenden Nachricht' (first matching message only), which is a meaningful selectivity behavior, and mentions the Kopf fields returned. It does not disclose error behavior when no message matches, or pagination/truncation limits, but the core selectivity disclosure is valuable given zero annotation coverage.

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 compact three-sentence German paragraph that efficiently covers purpose, use case, and a required-parameter constraint. It's front-loaded with the core function. Slightly more text than strictly necessary but no wasted sentences or redundancy.

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 no output schema, the description helpfully lists the return content (From, Subject, Date header fields plus Klartext-Inhalt). The tool has moderate complexity with 4 optional parameters and no required ones; the description covers the key conditional requirement and use-case, though it could note what happens when no message matches or when both keys are absent. The output-format disclosure compensates well for the missing output schema.

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 all four parameters. The description adds the constraint that at least one of subjKey or senderKey must be provided ('Mindestens subjKey oder senderKey angeben'), which is meaningful semantic value beyond the schema, and explains the mailboxes default references search_messages. Since coverage is complete, baseline 3 is appropriate with the added conditional requirement noted.

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 verb ('Liefert den Klartext-Inhalt'), the specific resource ('der ersten passenden Nachricht'), and includes the returned content fields (Kopf with From, Subject, Date). It distinguishes its purpose from siblings by explicitly targeting messages where evidence lives only in the mail body without a PDF attachment, differentiating it from save_attachment and search_messages.

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 description explains when to use it ('Für Belege, die nur im Mailtext stehen und kein PDF anhängen'), giving clear selection context relative to alternatives. However, it lacks explicit when-NOT-to-use statements or named alternative tools as exclusions, and does not mention how mailboxes default differs from search_messages beyond a passing note in the schema.

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