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

Annotations already mark this as read-only and idempotent, and the description adds useful behavior beyond that: version-dependent execution ('On bridge module 8.11.0+ the selection happens inside Foundry; on older modules the full pack is fetched'), pagination behavior, and the AND combination of types and ids. No contradiction with annotations exists.

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?

Every sentence earns its place: purpose, prerequisite, parameter semantics, version behavior, pagination, and alternative routing. The most important usage facts are front-loaded, and there is no fluff 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?

For a read-only browsing tool with no output schema, the description covers all six parameters, pagination, filtering, batching, version-dependent behavior, and sibling-tool distinctions. Nothing essential to invoking the tool correctly is missing.

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?

Although schema coverage is 100%, the description adds meaning not present in the schema: 'types+ids combine with AND,' ids are for batch-fetching in one call, and it gives a concrete example ('every item a class grants, taken from uuid-resolve output'). This materially helps an agent construct correct calls.

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 opens with a specific verb and resource: 'Browse the contents of a compendium pack. Lists documents (monsters, items, spells, etc.).' It also differentiates itself from nearby siblings by explicitly pointing to compendium-list for pack discovery, compendium-document-get for single-document fetching, and the dnd5e/pf2e filter tools for structured stat filters.

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?

It gives explicit routing guidance: 'Use compendium-list first to find the packId,' 'instead of N compendium-document-get calls,' and 'For structured stat filters... prefer dnd5e-compendium-filter-* / pf2e-compendium-filter-* instead.' This tells the agent when to use this tool and when to choose a clear alternative.

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