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

Beyond the readOnly/idempotent annotations, the description reveals useful behavioral traits: unset `kind` searches all classifications and is the most expensive call, rows are ordered by kind then code, and there is no sort argument. This prevents the agent from inventing a sort parameter and sets clear performance expectations.

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 tightly written and front-loaded with the core purpose in the first sentence. Every subsequent sentence earns its place: cost guidance, when to set `kind`, and the no-sort behavior. It is appropriately sized for a tool with five parameters.

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 the rich annotations, fully described schema, and output schema, the description covers the remaining practical concerns: use case, cost, paging, ordering, and absence of sorting. Nothing the agent needs to invoke the tool correctly is missing.

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%, so the baseline is 3. The description adds meaningful guidance beyond the schema, especially for `kind` (unset means all classifications and is expensive; set it when the question names one). It also disambiguates the pagination intent with the "no sort" note. This lifts it above baseline.

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 resource (fiscal codes) and the two main actions: searching by description and paging through the table. The example "what NCM is a keyboard" makes the purpose concrete, but it does not explicitly contrast with sibling tools like lookup_fiscal_code or list_fiscal_kinds, which keeps it just 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?

The description gives excellent usage context: prefer this lookup over guessing from memory, and set `kind` whenever the question already names one to avoid the most expensive call. It lacks explicit when-not-to-use statements naming sibling alternatives, so it stops short of fully explicit routing.

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