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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, but the description adds concrete, decision-relevant context beyond them: 'Costs nothing, spends no credits, calls no provider.' That tells the agent this is a zero-side-effect dry run, which the annotations alone only imply.

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 tight sentences, front-loaded with the core definition, then the cost guarantee, then the usage rule. No filler; every clause carries weight.

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 9-parameter preview tool with no output schema, the description usefully names what comes back (price plus resulting aspect/duration), which is the key return information an agent needs. It does not enumerate the full response shape, but that is minor given the rich schema coverage.

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?

Schema description coverage is 89%, so the schema already documents nearly all nine parameters with real guidance (e.g. workspace key scoping, project charging, overrides semantics). The description adds nothing parameter-specific beyond echoing 'aspect/duration', so the baseline 3 applies.

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?

States a specific verb (price) and resource (a clone) and immediately scopes it as non-creating: 'Price a clone WITHOUT creating it.' This cleanly distinguishes it from clone_template, which is the actual creation sibling.

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?

Explicitly names the alternative and the ordering: 'Use this before clone_template so the user knows the price...' The agent knows both when to call it and which sibling it precedes, with the reason spelled out.

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