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

readOnlyHint=true already covers the safety profile, and the description adds genuinely new behavior: facet results include matching page counts and carry no document bodies, and large facets are paginated via cursor. It stops short of describing error or empty-facet behavior, so not a 5.

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, front-loaded with the purpose and the relationship to search_docs. No wasted words; each clause carries distinct information.

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?

An output schema exists, so return values need no explanation, and the core call-then-paginate workflow is conveyed. However, for a 9-parameter tool with near-zero schema documentation, the description leaves a lot of interactive behavior (how filters narrow the facet listing) unexplained.

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?

With only 11% schema description coverage across 9 parameters, the description must carry more weight than it does. It explains facet, limit, and cursor (continuation), and the facet enum is self-documenting, but the filter parameters (framework, version, package, tags, locale, audience) and how they scope the returned facets are never described.

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 and resource ('List valid framework, version, package, and tag filters with matching page counts') and explicitly positions itself relative to a sibling by saying to call it 'before calling search_docs.' An agent can distinguish it from search_docs and list_docs without opening any schema.

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 sequencing guidance ('before calling search_docs') and the pagination instruction ('Use facet, limit, and cursor to continue a large facet without document bodies') give clear usage context. There are no explicit when-not conditions, but the workflow role is unambiguous.

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