Get billing summary

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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds meaningful behavioral context by specifying that the summary includes 'current usage and live spend', implying real-time data rather than cached values. This goes beyond what annotations provide without contradicting them.

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 sentence of about 20 words that front-loads the usage condition and specifies the exact resource and data scope. There is no filler, repetition, or unnecessary detail.

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?

For a simple one-parameter, read-only tool with no output schema, the description covers the essential selection and invocation information: when to use it, what it returns, and the target resource type. It could optionally describe return format or billing period, but nothing critical is missing for an agent to decide and call the tool correctly.

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 zero description coverage for workspaceId, so the description must compensate. It says 'for a Lizard workspace', which implies the parameter is the workspace identifier, but it never explicitly states that workspaceId should be the target workspace ID. Since there is only one parameter and its name is self-explanatory, the gap is limited, but the description still leans on the parameter name rather than explaining semantics.

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 'Use this when the user wants a cost/billing summary for a Lizard workspace', which clearly identifies the action (getting a summary), the resource (billing for a workspace), and the scope (current usage and live spend). This distinguishes it from sibling tools like metrics_get, which is about general metrics rather than billing.

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 explicitly states when to use the tool: when the user wants a cost/billing summary. It does not name alternatives or exclusions, but the condition is clear enough that an agent can route to it appropriately; the lack of explicit when-not guidance is a minor gap.

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