cantrip_meter_balance

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 describes the return values (available, reserved, total credits) and hints at the tool's read-only nature through 'Check', but it does not detail potential errors, rate limits, authentication needs, or how 'reserved credits' are calculated. The description adds some context but leaves gaps in 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 front-loaded with the core purpose in the first sentence, followed by parameter guidance in the second. Both sentences earn their place by providing essential information without redundancy, making it efficient and well-structured for quick understanding.

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 low complexity (1 parameter, no output schema, no annotations), the description is mostly complete: it covers the purpose, return values, and parameter usage. However, it lacks details on error handling or edge cases (e.g., what happens if credits are negative), which would enhance completeness for a financial 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 has 100% description coverage for the single parameter 'project', so the baseline is 3. The description adds value by explaining the parameter's purpose ('overrides .cantrip.json') and when it's required ('Required in environments where cantrip_connect cannot write to the filesystem'), providing practical context beyond the schema's technical definition.

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 specific action ('Check remaining credits') and the resource ('credits'), distinguishing it from sibling tools like cantrip_meter_history or cantrip_meter_tiers by focusing on current balance rather than historical data or pricing tiers. It explicitly lists the three return values (available, reserved, and total credits), making the purpose unambiguous.

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 provides clear context for when to use the optional 'project' parameter ('useful in cloud-hosted or multi-project contexts'), but it does not explicitly state when to use this tool versus alternatives like cantrip_meter_history or cantrip_status. It implies usage for checking credit balances but lacks explicit exclusions or comparisons to siblings.

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