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

Annotations already declare the tool read-only and open-world; the description adds behavioral detail about validation and returning a manifest, plus the optional base64 ZIP behavior. It does not contradict annotations, and the functional behavior is reasonably transparent, though it does not mention error handling on invalid specs.

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 sentences with front-loaded purpose and no fluff. The description is extremely concise while covering the primary behavior and an optional feature.

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 9 optional parameters and no output schema, the description covers the core return (manifest of URLs) and the optional ZIP, but it lacks guidance on when to use this tool versus siblings, how a preset interacts with sizes, and what happens on validation failure. The description is adequate but leaves meaningful gaps.

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 67%, so most parameters already have meaningful descriptions. The tool description does not add further parameter semantics beyond the schema—it just restates 'multiple size specs or one preset' and 'inline a small SVG ZIP', both already present in the schema descriptions. Score is baseline 3 for medium coverage.

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 uses a specific verb ('Validate ... and return') and identifies the exact resource (manifest of PlacePack image URLs). It clearly distinguishes this tool from siblings: placepack_create_image creates a single image, while placepack_list_presets lists presets.

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 usage by stating 'multiple size specs or one preset', but it does not explicitly contrast this with sibling tools or provide when-not/when-to-use guidance. It is unclear whether this should be preferred over create_image for any multi-size need.

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