lookup_tax_document

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 exact-match only behavior, normalization of varying notation, NOT_FOUND when no exact match, separation of similarDocuments, and automatic classification of document types. This is highly transparent about expected behavior and edge cases.

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 concise and front-loaded with the main purpose. Every sentence adds value: principal function, document type coverage, normalization examples, NOT_FOUND/similarDocuments behavior, and usage priority. No fluff 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?

The description covers important edge cases (no exact match, partial overlaps), normalization rules, and document type scope. With an output schema present for return values, the description does not need to repeat those details. It is complete for both simple and complex scenarios.

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 baseline is 3. The description adds significant value for the document_number parameter by giving concrete examples of accepted notation variations and normalization, which goes beyond the schema. It does not add new meaning for body_limit or include_full_text, but the schema already describes those adequately.

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 tool's purpose: find documents by exact document number match and return the body. It distinguishes itself from siblings by emphasizing exact-match semantics and automatic normalization, and explicitly mentions it should be used before other tools when a document number is known.

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 provides explicit usage guidance: when you know the document number, always use this tool first. It also clarifies that partial matches are returned as similarDocuments and are not the answer, implicitly steering users to alternative search tools for fuzzy lookups.

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