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

Annotations provide readOnlyHint=true, and the description adds value by listing the specific return contents (metadata, coverage, freshness, tool guidance, first-query examples) and noting it is 'Free discovery'. It does not contradict annotations; it enriches the behavioral context without needing to restate the read-only nature.

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 two sentences with no filler. The first sentence front-loads the purpose and return contents, the second gives the when-to-use guidance. Every word earns its place.

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 one-parameter tool with no output schema, the description fully covers what the agent needs: what it returns, when to call it, and what to expect (paste-ready query). It is complete enough to invoke correctly.

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 has 100% coverage for the single parameter pack_id, with a clear description that it comes from get_catalog. The tool description adds no additional meaning beyond restating 'for one pack', so the baseline of 3 applies since the schema fully documents the parameter.

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 action (returns detailed metadata, coverage, freshness, guidance, and examples) and the resource (one pack). It distinguishes from siblings by explicitly targeting one pack and by mentioning 'preferred canonical tool guidance' and 'first-query examples', which are unique to this tool.

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 explicitly instructs to 'Call this before querying a new pack', providing a concrete trigger condition. However, it does not explicitly name alternatives or state when not to use it, though the context implies get_catalog is for listing and query_dataset for actual data.

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