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

Annotations already establish readOnlyHint and idempotentHint, so the safety profile is covered. The description adds useful behavioral context by noting that results depend on configuration ('recognized and enabled' and 'Corpus expansion is configuration controlled'), which tells the agent not to expect a static, fixed list.

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, both substantive: the first enumerates the returned data categories, and the second adds a meaningful configuration caveat. No wasted words, and the core functionality 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 zero-parameter, read-only tool, the description is nearly complete: it explains what data is returned and warns that configuration affects results. It does not describe the exact output format, but given the low complexity and rich annotations, this is not a significant gap.

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?

There are zero parameters and the input schema is empty with 100% schema description coverage, so the schema already fully accounts for invocation. The description adds no parameter-specific detail, but none is needed, making the baseline 4 appropriate.

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 identifies the operation ('Get') and the exact resource: recognized and enabled types, authors, language codes, and public subject labels. This enumerated set differentiates it from sibling tools like get_corpus_coverage or list_publications without needing to inspect their 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 implies it should be used when callers need available catalogue filter options, but it does not explicitly state when to prefer it over alternatives or mention any exclusions. Context is clear enough, but no sibling differentiation or 'when not to use' guidance is provided.

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