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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description adds real value beyond that by disclosing the shape of the response: per-area coverage plus an explicit notCovered list, which is important for a tool whose output has no schema.

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 purpose is front-loaded, but the second sentence is a ~150-word run-on that re-enumerates nearly every dataset the tool itself will report back. That content duplicates the return payload rather than guiding invocation, making the definition hard to scan.

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 single-optional-param, no-output-schema tool with full annotation coverage, the description is close to complete: it names the areas, the default behavior, and the notCovered guarantee. Only the sibling-comparison gap keeps it from a 5.

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 coverage is 100% and the single param already lists valid area values, so baseline would be 3. The description earns an extra point by clarifying the omit-for-all default behavior, which the schema description does not state, though it adds no further area-specific semantics.

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 intent: an introspection tool reporting what Data Butler covers and does not, per area, plus a notCovered list. The verb/resource pair is clear, but it never distinguishes itself from siblings like catalogue or domain_provenance, which could plausibly serve overlapping discovery needs.

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 parenthetical '(omit for all)' is a genuine usage instruction, and 'including figures it does not serve yet' hints at the pre-call check use case. However, there is no explicit statement of when to call this versus catalogue or domain_provenance, leaving sibling selection to inference.

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