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 useful structural fact that entries are partitioned by ruleset leg and are a subset of the vault catalog, but says nothing about pagination, ordering, or result size.

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 tight sentences, front-loaded with the core definition before the ruleset scoping detail. Nothing is wasted, though the term 'leg' is used without definition, slightly reducing immediate clarity.

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 only two parameters, full schema coverage, and an output schema that carries return values, the description covers what an agent needs to invoke the tool correctly. The remaining gap is the absence of any routing guidance against the large set of sibling list tools.

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 both parameters are already documented in the schema. The description's explanation of `ruleset` largely restates the schema's own description, adding no syntax or format detail beyond it, so the baseline 3 applies.

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?

States a specific verb+resource ('List the campaign's house spells') and clarifies the semantic scope ('active house-rule associations' and 'subset of the broader vault catalog'), which distinguishes it from vault_search_spells. It does not explicitly name a sibling tool, so it falls short of a 5.

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 explains how to use the `ruleset` parameter (omit to union all legs, set to scope to one leg), which is usage guidance, but it never says when to choose this tool over the sibling vault_search_spells or how it relates to play_list_campaign_rules. Usage is implied rather than delineated.

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