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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered upstream. The description adds only the endpoint path (POST /v1/locale-value-parser) and the EU/US framing; it does not disclose behavior on unparseable input, error shapes, or how ambiguous formats are resolved. That is modest added value above the annotations, hence a 3.

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 compact sentences with the capability front-loaded and the endpoint appended. There is minor redundancy — the first clause largely restates the annotation title — but nothing extraneous enough to impede selection.

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?

There is no output schema, so the description carries the burden of explaining the returned structure, yet it says only "structured JSON" without naming fields, units, currency representation, or confidence. For a two-parameter parser with clean annotations this is adequate to select and invoke the tool, but an agent cannot predict the response shape.

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 parameters are already documented with examples in the schema itself, making 3 the baseline. The description's only added semantic content is the "EU/US" framing, which loosely hints that locale_hint controls decimal/date interpretation, but it never states accepted locale values or what happens with an unsupported hint.

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 names a specific verb (normalize/parse) and a concrete resource set — EU/US prices, dates, percentages, measurements — plus the output form (structured JSON). That clearly separates it from siblings like tinplate_eu_vat_calculator or tinplate_invoice_validator. It stops short of explicitly contrasting with any named alternative, so a 4 rather than 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?

Usage is implied by the phrase "messy EU/US prices, dates, percentages, and measurements," which tells the agent this is for locale-formatted free text. There is no explicit when-not-to-use guidance, no mention of what to do for non-locale-formatted or plain numeric input, and no named alternative for overlapping tasks such as invoice validation.

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