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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds valuable context about return shape (array, one element per filed year) and the specific financial fields included, helping the agent set expectations. No additional edge-case behavior is disclosed, but annotations cover safety profile.

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 well-structured sentences with a concrete example. The main purpose is front-loaded, and every sentence contributes useful information without 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?

For a simple single-parameter tool with no output schema, the description covers the key aspects: source, input example, and return structure. It does not specify behavior for missing or invalid org numbers or empty results, but these are minor gaps given the tool's simplicity.

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% with a clear description for orgnr, so the parameter is fully documented. The description repeats the example without adding significant new meaning beyond the schema. Baseline of 3 is appropriate for high schema coverage.

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?

Clearly states the tool retrieves annual financial statements for an entity by 9-digit org number, specifying the resource and scope precisely. This distinguishes it from sibling get_* tools like get_entity, which would return general entity information.

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 implicitly conveys when to use the tool: whenever financial statements are needed for a given org number. It does not explicitly contrast with alternatives or mention exclusions, but the specificity makes the use case obvious. Lacks explicit when-not-to-use guidance, preventing a 5.

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