compare_values

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

With no annotations, the description carries the full burden, and it does disclose useful behavior: results are 'latest' records, 'source-backed', sorted fastest first, and labeled with collection status. However, it omits handling for missing data in some countries, auth/rate-limit requirements, and the shape of the 'collection status' label.

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 action and resource, with no filler. It packs sorting and labeling details efficiently, though the clause stacking makes it slightly harder to parse at a glance.

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 tool with no annotations and no output schema, the description covers the result ordering and labeling but leaves service_key's format, error behavior, and partial-data handling unspecified. It is adequate but not fully self-sufficient.

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 only 50%: applicant_countries is documented as ISO alpha-2 codes with an example, but service_key has no schema description at all. The description says 'for one service' but never clarifies whether service_key is an ID, slug, or name, so it fails to compensate for the undocumented parameter.

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 gives a specific verb (compare) and resource (latest source-backed processing-time records) with explicit scope (one service across several applicant countries). It is clear what the tool returns, though it does not explicitly name or contrast itself with the sibling get_latest_value, which likely covers the single-value case.

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 phrase 'across several applicant countries' implies the multi-country comparison scenario and distinguishes it implicitly from get_latest_value, but there is no explicit when-to-use/when-not statement or named alternative. The agent must infer the selection condition.

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