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

With no annotations, the description carries the full burden. It discloses the outputs produced and the optional live-registry verification, but leaves compliance checking vague: it doesn't say what FDA GUDID / EU MDR checks are performed, what happens on a non-compliant or unparseable UDI, whether 'live' requires network access, or whether failures raise errors or are reported in the result.

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?

A single dense sentence that front-loads the core action and layers optional detail after semicolons; nothing is wasted, though the sentence is long enough that a period before the optional live-verify clause would read slightly better.

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 low-complexity two-parameter read tool with no output schema or annotations, the description covers the input formats, the decoded output fields, and the optional live path, which is most of what an agent needs. Remaining gaps are failure semantics and the specifics of the compliance checks.

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 'udi' and 'live' are already documented in the schema with an example string. The description restates the live-verification behavior but adds no syntax, format, or edge-case detail beyond the schema, matching the baseline of 3.

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?

States a specific verb (Decode) and resource (UDI string), names the three supported carrier standards (GS1, HIBCC, ICCBBA), and specifies the decoded outputs (DI, lot, serial, expiration). It also clearly differentiates itself from the sibling decode_gs1 by spanning multiple carrier formats and adding compliance checks.

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 implies when to use it (decoding a UDI carrier) and notes the optional live-GUDID path, but never states when to prefer this over the sibling decode_gs1, nor any exclusions or prerequisites. Usage is inferable rather than explicit.

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