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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavioral context beyond them: the text is checked in memory and not stored, and the tool never asserts a sheet is correct in content. It stops short of describing the shape of the result, which matters since there is no output schema.

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 core scope and the list of checks are front-loaded, and the two trailing sentences carry the privacy and limitation caveats. The reference to the equivalent page '/de/sdb-check' is slightly extraneous but short enough not to distract.

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-parameter, read-only check with no output schema, the description covers what is checked, what input is expected, that nothing is stored, and the key limitation on the verdict. Only the form of the returned result is left implicit.

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 both the text and language parameters are already documented in the schema. The description adds only the framing that the text should be the extracted PDF text, which is a modest increment over the schema's own wording; 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?

The description uses a specific verb ('Formal check') on a specific resource ('the text of a safety data sheet') and enumerates the exact checks performed: Annex II / Regulation (EU) 2020/878 subsection presence, UFI and CAS check digits, non-CLP hazard codes, revision date and version. This lets an agent distinguish it from siblings such as check_identifier_codes or check_gpsr_information without opening a schema.

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?

It clearly states the required input context ('Pass the extracted text of the PDF') and scopes the tool as a formal, not content, check. It does not explicitly name alternatives or say when not to use it (e.g. versus identifier-code checking), so the routing guidance is clear but not exhaustive.

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