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

Annotations already cover read-only and non-destructive behavior. The description adds that data comes back 'as it is' and that write operations refuse, but it does not explain the output structure or how to interpret the result. This is some added context but not comprehensive.

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 verbose, with a long sentence including a URL and cryptic phrases like 'a live seat on The Wall'. It front-loads the purpose but then becomes dense and could be tightened. It earns its place mostly, but not every word is necessary.

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?

No output schema exists, so the description should explain what the tool returns and how to interpret 'can be paid'. It fails to do so, and the input format is vague ('in the shape it arrived'). For a tool with no schema, this is a significant 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?

With an empty schema (0 parameters), the description provides the only meaning by indicating the input is an invoice or payment intent in its raw shape. This is essential guidance, though it lacks detail on the expected structure. Baseline for 0 params is 4, and this description meets that.

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: checking whether a payment can be paid before signing. It specifies the resource (invoice or payment intent) and distinguishes itself from siblings by emphasizing read-only behavior and payment-specific scope.

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?

Provides a clear trigger context ('Before signing a payment somebody else asked you to make') but does not explicitly name alternatives or when not to use it. The read-only constraint is implied but not compared to other payment-related tools.

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