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

Annotations already indicate a non-read-only, non-destructive, idempotent operation. The description adds cost ($0.10 / 1 GCX), mode details (XMP/IPTC, C2PA, soulmark, hash registration), and the ExifTool implementation, which are useful beyond the annotations. It does not disclose output/return behavior, but the annotations cover the core safety profile.

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 description is compact, front-loaded with the main action, and every sentence adds value. Mode explanations and cost are provided without unnecessary elaboration.

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 3 parameters, a nested metadata object, and no output schema, the description covers modes but omits return behavior and prerequisites. It references enrich_metadata in the schema, aiding workflow context, but gaps remain regarding what the tool outputs or how the image is modified.

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%, so the schema already explains all parameters. The tool description adds marginal detail about the full_gcx mode (e.g., XMP-gc namespace, C2PA, soulmark), but does not significantly change parameter understanding. Baseline 3 is appropriate.

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 clearly states the tool's purpose with a specific verb ('Embed metadata into image') and mechanism ('via ExifTool'). It distinguishes this tool from siblings like enrich_metadata and watermark_embed by focusing on the infusion step and naming two distinct modes.

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 description implies use when metadata needs to be embedded, but it does not explicitly contrast with sibling tools or state when not to use it. The two modes provide internal guidance for standard vs full_gcx, but no alternative tool selection criteria are mentioned.

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