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

Annotations only indicate idempotentHint=true and readOnlyHint=false, but the description adds critical nuance: the first call for an organisation writes (opens wallet, grants credits, records ledger line), while all subsequent calls are read-only. This is beyond what annotations convey and is essential for correct usage.

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 compact yet information-dense. Each sentence serves a purpose: the first defines output, the second lists free operations, the third gives usage guidance, and the fourth clarifies the write-on-first-call behavior. It is front-loaded with the core purpose and avoids fluff.

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 no parameters and an existing output schema (not shown but present), the description fully covers what an agent needs: the tool's purpose, when to use it, side-effect behavior, and cost implications. No critical information is missing for a tool of this simplicity.

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?

There are zero parameters and the schema coverage is 100%, so no parameter documentation is needed. The description focuses on output content and usage context instead, which is appropriate. Baseline for zero params is 4, and the description adds no param-specific details (none needed).

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 opens with a precise statement of what the tool reports: credit balance, signed-statement coverage, and spent amount. It clearly differentiates from sibling tools by focusing on wallet/account status rather than on specific actions like checking plots or looking up references, naming those free operations explicitly.

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?

Explicit guidance is given: 'Use this before starting a batch of compiles so the user is not surprised part-way through.' It also clarifies which operations are free versus which draw down the balance, giving the agent a concrete decision rule for when to invoke this tool.

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