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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds batching behavior and the fact that each check is independent with its own decision/evidence/receipt, but does not explain the unusual idempotentHint=false for a read-only check or any rate/cost implications.

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 tight sentences with zero filler; the batch limit and independence constraint are front-loaded before the return-shape note.

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?

An output schema exists, so the mention of decision/evidence/receipt per result is a slight redundancy rather than a gap. For a batch wrapper over a well-documented nested schema, the definition is nearly complete, lacking only explicit routing against single-check siblings.

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?

The top-level 'checks' parameter itself carries no schema description, so the description's 'up to 25 independent checks' does add meaning. The nested fields (existing, candidate, ids, detail) are well documented inside the schema, so the description only needs to frame the container, which it does minimally.

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+resource ('compatibility checks') with a clear batching scope ('up to 25 ... in one call'). The phrase 'in one call' implicitly contrasts with the singular check_compatibility sibling, but does not name it.

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 example ('ranking candidate products for one device') implies a batch use case, and 'independent checks' hints at when batching is appropriate. However, there is no explicit when-to-use/when-not guidance or named alternative versus check_compatibility or check_fit.

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