get_adcp_capabilities

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds useful behavioral context by relating the discovery behavior to AdCP 3.0 and listing what capability areas are exposed, such as spec compliance, HTTPS enforcement, and wrapper depth.

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 three sentences, front-loaded with the core purpose and purpose-driven usage context, with no filler or redundant restatement of tool name or schema fields.

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?

Combined with the detailed schema coverage, rich annotations, and existing output schema, the description gives an agent enough context to understand when to call this tool and what it returns. Nothing critical is missing.

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 100%, with both parameters already explaining their filtering behavior and defaults. The description does not add parameter-level meaning beyond what the schema already documents, so the baseline of 3 is appropriate.

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 returns AdCP version, supported protocols, and governance capabilities, with a specific resource ('this vastlint agent'). It conveys the tool's discovery nature, though it does not explicitly differentiate from the sibling validation tools.

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 says 'Call this first when integrating vastlint into an AdCP creative pipeline,' giving clear contextual guidance for when to use it. It does not discuss exclusions or alternatives explicitly, so it stops short of full when-to-use versus sibling-tool guidance.

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