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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so the safety profile is covered. The description adds meaningful non-structured context: the data is hand-verified, it is licensed CC-BY-4.0, and each result carries an infrabase_url for attribution — licensing and provenance details an agent could otherwise get wrong.

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?

Three short sentences that front-load what the tool returns and its scope, followed by filter behavior and licensing. No filler; every clause carries information an agent needs.

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 an optional-filter list tool with no output schema, the description covers scope, filtering, licensing, and one result field. It does not mention result volume, ordering, or pagination behavior, a minor gap given the tool's simplicity and its read-only annotations.

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% with self-documenting enums, so the baseline is 3. The description adds real value by framing both parameters as optional narrowing filters ('Optionally narrow by category or job'), clarifying that omission returns the full European set rather than being an error.

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 (List) plus a precisely scoped resource (AI infrastructure providers headquartered in Europe) and the question it answers (data residency and sovereignty). This is clearly distinguishable from siblings like search_tools or find_alternatives, which are not geography-scoped directory listings.

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?

Gives a clear use context ('for data residency and sovereignty questions') and explains that the two filters are optional narrowing mechanisms. It stops short of naming an alternative sibling or stating when not to use this tool, so it is strong context without explicit routing.

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