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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that results are scoped to the calling account and limited to recent items, but says nothing about ordering, default page size, or whether further results can be fetched.

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?

One short, front-loaded sentence with no filler. Its brevity is efficient, though the same terseness is what leaves usage and parameter gaps unaddressed.

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 two-optional-parameter read tool with annotations covering safety and no output schema to explain, the description is minimally adequate. It is still thin on result ordering, default limit, and how this differs from the single-letter status tools.

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?

Only the "reference" parameter carries a schema description, leaving "limit" (1-50) undocumented in both places. The description never mentions either parameter or explains that limit caps how many recent letters are returned, so it fails to compensate for the 50% coverage gap.

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 gives a specific verb ("Lister") plus resource ("breve") and a clear scope ("seneste breve sendt af denne konto"), so an agent knows it retrieves a recent-sent list rather than a single letter. It does not name or contrast with siblings like get_letter_status or get_order_status, which is why it stops short of a 5.

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?

There is no when-to-use guidance, no exclusions, and no mention of alternatives among the six sibling tools. The agent must infer from the phrase "seneste breve" alone that this is the bulk-list tool versus the single-item status tools.

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