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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that the tool performs a 'live check' (indicating a network call) and returns health and evidence, but it omits potential side effects, authentication requirements, or rate-limit behavior. Some context is given, but not enough to fully inform the agent of behavioral traits.

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 a single, front-loaded sentence that immediately states the action and expected outputs. There is no redundancy or filler; every phrase adds value. This is a model of conciseness.

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 moderate complexity (2 parameters, no output schema, no annotations), the description covers the core action and output shape but misses usage guidance and parameter semantics. It is adequate for a simple verification tool but leaves gaps an agent would need to infer or otherwise discover.

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 schema has no descriptions and the overall schema_description_coverage is 0%. The description does not elaborate on merchant_id or rail beyond their literal names, nor does it explain the significance of the rail enum values or how they affect the check. Since the description fails to compensate for the lack of schema documentation, parameter semantics are weak.

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 a specific action ('Run a live check') on a specific resource ('a merchant's declared payment endpoint for a rail') and indicates the return type ('health, detail, and rail-specific evidence'). This distinctly differentiates it from sibling tools like get_merchant, list_rails, and search_merchants, which are read/info 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 implies its use case (verifying a payment endpoint) but does not explicitly state when to use it over alternatives or when not to use it. There is no mention of prerequisites like a valid merchant_id or supported rail, and no exclusions are provided. This is implied rather than explicit, so it earns a mid-range score.

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