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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds the key behavioral detail that actors are transformed into statblocks while other types return core fields plus system data, which is meaningful context beyond the annotations.

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?

Three sentences with no filler: the first states purpose and output behavior, the second routes to alternatives, and the third tells how to find the required ID. The most important information is front-loaded.

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 simple read-only tool with two well-documented parameters, the description fully covers what the agent needs: what the tool returns, how it formats different document types, and how to find inputs. No output schema exists, but the description compensates by describing the return shape.

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 documents packId and documentId. The description adds value by telling the agent how to source document IDs via compendium-browse and clarifying that filter tools return UUIDs, which helps populate parameters correctly.

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 a specific verb and resource ('Get a compendium document') and immediately clarifies it returns a readable summary rather than raw data. It distinguishes itself from compendium-document-get-raw and uuid-resolve, so an agent can tell them apart without opening schemas.

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 gives explicit routing guidance: use this tool for readable summaries, use compendium-document-get-raw for complete raw JSON, use uuid-resolve when already holding a UUID, and use compendium-browse to find document IDs. This fully covers when to use the tool versus its alternatives.

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