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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses real behavioral traits: the C2PA signer is not yet verified against a trust list, results are confidence-based and never a definitive not-AI verdict, format coverage differs by signal family, and `checks_run` records what ran per file. It also states the per-image price.

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?

The definition is dense but front-loaded, leading with what is read and validated before moving to limitations and format scope. Every sentence carries information, though the trailing pricing and boilerplate tool-name mention add slight clutter.

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?

With no output schema, the description does the work of describing results: signals plus confidence, flag categories, and the `checks_run` field. Given a one-parameter tool with full safety annotations, this is close to complete; the exact response shape (e.g., confidence scale) is only loosely characterized.

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 only a single parameter, and the schema already documents it fully (base64 bytes, max 4 MiB). The description adds useful meaning by enumerating the file types the parameter can accept (images, PDF, Office/OpenDocument, audio, video, with a narrower list for IPTC/XMP/EXIF signals), which helps the agent decide whether a given file is worth submitting.

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 specific verbs and resources: it reads and validates C2PA manifests (signature and hashes), IPTC DigitalSourceType, and generator metadata, then flags stripped, invalid or conflicting credentials. An agent knows exactly what the tool inspects. It stops short of distinguishing itself from the sibling `verify_provenance`, 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 context is implied through the supported-format lists and the caveat that the tool reports signals rather than a definitive answer. However, there is no explicit when-to-use or when-not-to-use guidance, and no mention of the sibling `verify_provenance` as an alternative, leaving the agent to infer routing.

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