defender_get_capabilities

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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description reinforces and extends this by stating 'The probe only reads; the result is kept until refresh.' It also discloses caching/refresh behavior and the categories of checks performed, which adds genuine behavioral context beyond the annotations.

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 dense but every sentence earns its place: purpose, usage timing, interpretation semantics, return fields, and refresh behavior are all covered. The key directive 'Call it once before investigating' is front-loaded. Slightly long-winded in the middle, but nothing is redundant.

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?

With no output schema, the description carries the burden of explaining return values, and it does: `capabilities`, `data_sources`, and `probe` are each described with their meaning. It also explains the real-world interpretation of empty results, which is critical context for an agent deciding whether a downstream query returned nothing due to a real 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?

Schema coverage is 100%, so the baseline is 3. The description adds value by explaining the 'result kept until refresh' caching mechanism, which clarifies what the `refresh` boolean does in practice. This contextualizes the parameter beyond the schema's 'Probe the tenant again instead of returning the last result.'

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 states a clear verb+resource: it probes what the tenant exposes as a capability binding, checking hunting tables, APIs, and permissions. It is distinctly a visibility/meta tool among siblings that fetch specific entities (machines, vulnerabilities, software). It never names a sibling explicitly, but the 'call it once before investigating' framing makes its unique role unmistakable.

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 gives concrete usage direction: 'Call it once before investigating.' It also explains the decision-relevant outcome—interpreting empty query results as visibility gap, missing licence, or missing permission. It does not list exclusions or explicit alternatives, but the 'call before investigating' directive is sufficient for a tool with no close sibling.

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