pbi_capabilities

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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds valuable behavioral context by detailing what information the tool reveals (live layer status, write permissions, engine version constraints) and that it provides reasons for unavailable capabilities, which goes beyond the structured metadata.

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 concise and front-loaded: first sentence states the core purpose, second elaborates on specifics. Every sentence carries useful information with no redundancy or filler.

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?

Given the tool's simplicity (no params) and the presence of an output schema, the description adequately covers its purpose and key behavioral facets. It could mention what happens when the live layer is unavailable, but the output schema likely covers such details.

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 has zero parameters and the schema coverage is 100%, so there is nothing to explain. With no parameters, the baseline is 4, and the description appropriately focuses on the tool's output rather than input 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?

The description clearly states the tool's function: to report what capabilities are currently available and what are not, with reasons. It specifies concrete aspects (live layer availability, .pbip writability, engine-version-dependent capabilities), distinguishing it from sibling tools like pbi_report_capabilities which likely focus on report-specific capabilities.

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?

Explicitly says an agent should consult this tool before planning, giving a clear when-to-use directive. It does not mention when not to use it or name alternative tools, but the context is strong enough to guide appropriate usage.

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