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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description contributes the return content (date, status, reserved amount), which is genuinely useful, but says nothing about ordering, volume or pagination behavior.

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?

Two short sentences with the core resource and returned fields front-loaded; nothing is padded. The German/English duplication is redundant for a single reader but serves a bilingual client base, so it costs little.

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 one optional parameter, annotations covering safety and no output schema, the description is nearly sufficient — it even enumerates the return fields in place of an output schema. Only the lack of paging/ordering hints keeps it short of complete.

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% and the single optional statusFilter already carries its own enum documentation and description. The prose adds no extra meaning about filtering semantics or what an unfiltered call returns, so the schema does all the work and baseline 3 applies.

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?

Names a specific verb and resource ('Listet die geplanten Sendungen des Partners') and adds the returned fields, so an agent knows exactly what the call yields. It does not, however, distinguish itself from siblings like letter_list or letter_schedule, which also surface scheduled mail.

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 only implied: the tool is a read-only list of schedules, and the statusFilter enum hints at narrowing results. There is no statement of when to prefer this over letter_list or when to call schedule_cancel instead, and no mention of paging or result limits.

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