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

Annotations already cover the read-only, idempotent, non-destructive profile, so the bar is lower. The description still adds real behavioral value: it scopes what is reported (coverage, unresolved authority links, sanitized refresh status) and warns that missing catalogue metadata is not evidence of real-world absence, which meaningfully shapes how an agent should treat the output.

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 compact sentences, front-loaded with the reported facets and closed with the interpretive warning. Slightly dense and telegraphic, but no sentence is wasted and nothing is buried.

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-argument diagnostic tool with an output schema and full annotation coverage, the description supplies what is needed to invoke it correctly and to interpret the results. The only meaningful omission is any when-to-use framing relative to the many sibling lookup 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?

The tool takes no parameters, so the baseline for this dimension is 4. The description introduces no parameter concepts that need elaboration and correctly stays at the level of what the call returns.

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 names the resource (data coverage) and enumerates the specific facets reported: coverage gaps, missing metadata, unresolved loaded-authority links, and refresh status. 'Snapshot' is used loosely as a verb, but combined with the title 'Inspect data coverage' the agent understands this is the diagnostic view over catalogue quality. It is clearly distinct from the domain-lookup and search siblings.

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?

There is no statement of when to call this versus alternatives (e.g. get_snapshot_changes, list_collections) and no prerequisites. The closing sentence is a caveat about interpreting results, not guidance on selecting the tool, so the agent gets no routing help.

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