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

Beyond the readOnly/idempotent annotations, the description discloses the required module version, that returns include raw document data, that UUIDs are not guessed, and that missing or malformed UUIDs return a specific error message. This is valuable 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?

The description is front-loaded with the core purpose, then organized into WHEN TO USE and LIMITS sections. Every sentence adds operational value, and there is no filler or repetition.

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?

Given a single parameter and no output schema, the description explains what is returned, the supported UUID forms, the error behavior, and required module version. An agent has enough information to invoke the tool correctly and interpret results.

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 schema already documents the 'uuid' parameter with examples, so the baseline is 3. The description adds useful guidance: UUIDs must be absolute, should be sourced from other tools' uuid fields, and relative UUIDs are unsupported. This goes beyond the schema.

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: resolve any absolute Foundry UUID to its full document. It enumerates supported UUID shapes (Actor, Compendium, embedded), which differentiates it from sibling tools that target specific document types or require structured lookups.

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 'WHEN TO USE' section gives explicit scenarios such as walking a reference graph or fetching a page found by compendium-page-search. It also has a LIMITS section excluding relative UUIDs, but it does not explicitly name alternative sibling tools for cases where a structured lookup would be preferable.

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