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

No annotations are provided, so the description bears the full transparency burden. It discloses the monetary cost (1 api_sat per call), the pre-verification step via debit_or_deny, and the output form (dark-themed SVG with specific visual elements). This goes beyond a minimal description and gives the agent meaningful behavioral expectations.

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?

Three sentences, all substantive. The first sentence front-loads the core operation, the second explains the output and its relation to the sibling tool, and the third covers cost and verification. No filler or repetition.

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 an output schema exists, the description does not need to enumerate return values. It covers the essential invocation context: what the output is, how it relates to a sibling, the cost, and the pre-cost verification requirement. An agent has enough information to decide whether and how to call this tool.

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 input schema provides 100% description coverage for all parameters, so the baseline is 3. The description adds no new parameter-level meaning: it only mentions the data source for the statement, while parameter details like days, npub, and dpop_token are already fully documented in the schema.

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 specific verb ('Generate') and a concrete resource ('visual SVG infographic of your account statement'). It explicitly distinguishes itself from the sibling authority_account_statement by saying it returns the same data rendered as an SVG, which makes the tool's purpose 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?

It names the alternative authority_account_statement directly and clarifies the relationship by noting the same data is returned but rendered as an SVG graphic. It does not state an explicit 'use this instead of X when...' rule, but the visual-vs-data distinction is clear enough for an agent to choose appropriately.

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