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

Annotations already cover read-only, idempotent, open-world, and non-destructive behavior. The description adds valuable non-obvious behavioral context beyond the annotations: all monetary inputs must be in the same currency, the tool works 'from explicit assumptions,' and the returned canonical_url should be cited. No contradiction with annotations exists.

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 two sentences with no filler. The first sentence front-loads the core purpose and outputs; the second provides usage context and key constraints. Every sentence contributes information an agent needs.

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?

The tool has 13 required parameters and an output schema, but the description is complete enough for selection and invocation: it states the purpose, the use case, the key cross-parameter constraint, and the citation expectation. The output schema and complete parameter schema cover the remaining detail, so nothing critical is missing.

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 100%, so the schema already documents all 13 parameters and their meanings. The description reinforces that monetary inputs should share a currency, which is useful, but it does not add per-parameter semantics beyond what the input schema provides. Baseline 3 is appropriate.

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 names a specific verb ('Calculate') and a specific resource ('operational economics of an AI agent'), then enumerates concrete outputs: monthly operating cost, cost per verified outcome, savings, ROI, and break-even success rate. It also distinguishes itself from sibling calculation tools by scoping to 'an agent business case or scenario comparison'.

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 says 'Use this for an agent business case or scenario comparison,' which gives clear context for when the tool is appropriate. It does not explicitly state when not to use it or name alternatives like calculate_human_supervision_capacity or calculate_evaluation_sample_size, so it stops short of a full 5.

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