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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety and idempotency profile is fully covered. The description's remaining substance is largely return-shape detail (fields, up to 20 variants), which the existing output schema already carries; the 20-variant cap is the one piece of genuinely additive behavioral context.

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?

Front-loaded with the usage trigger, then the return payload, then the exclusion. Three sentences with no filler, though the enumeration of returned fields is somewhat redundant given the output schema.

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 read-only, single-parameter lookup with a full output schema and rich annotations, the description covers trigger, scope and exclusion adequately. The only mild gap is not naming list_batches as the multi-batch alternative.

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?

There is a single required parameter with 100% schema description coverage ('Exact batch id'), so the schema already does the work. The description adds nothing about the id's format or source beyond what 'one existing batch' implies, which is the expected baseline here.

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 (read) and resource (output metadata and first-party file links for one existing processed-image batch), and the phrase 'one existing batch' implicitly separates it from the list_batches sibling. It stops short of naming list_batches or delete_batch, so the sibling differentiation is left partly to inference.

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?

'Use this when the user wants to read ... for one existing ... batch' gives a clear trigger condition, and 'Not for resizing or converting a new image' supplies an explicit exclusion. Neither names the actual sibling tool an agent should fall back to, so it is clear context without full alternative routing.

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