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

Annotations already declare read-only, idempotent, non-destructive, and closed-world. The description adds genuinely new behavioral facts: the result is non-secret, no test objects are ever written, and the bucket check does not validate job/artifact reads or writes. There is a mild tension between openWorldHint=false and performing a HeadBucket against storage, but the description does not claim an external interaction, so this is not a direct contradiction.

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?

Three tight sentences with no filler. The identity and safety framing come first, then the default behavior, then the parameter escalation and its limits.

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 not be restated, and the description covers the safety profile, the two operating modes, and the scope limits. The only gap is not specifying which configuration items are validated, which is minor for a diagnostic with zero required parameters.

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 description coverage is 0%, so the description carries the burden for the single check_bucket parameter. It supplies the missing semantics: false/default means configuration-only, true triggers a HeadBucket call, and the probe has defined limits. This compensates well for the bare schema, though it does not describe the response payload.

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: a read-only, non-secret storage diagnostic, with a clear distinction between configuration checking and bucket checking. No sibling tool overlaps this purpose, so differentiation is implicit rather than explicit, but an agent can identify what the tool does.

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?

Explains that the default mode only checks configuration and that check_bucket=true escalates to a HeadBucket probe, which tells the agent which mode to request. It also bounds expectations ('Bucket access does not verify job/artifact reads or writes'), giving a clear when-not-to-rely-on-it cue, though it names no alternative tool.

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