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

Annotations already mark the tool as read-only and not open-world, and the description adds meaningful behavioral context: omitted inputs fall back to calculator page defaults, and the output is characterized as 'back-of-the-napkin math, not accounting advice.' This goes beyond the annotations 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 three concise sentences that front-load the core purpose, then cover defaults, outputs, and a caveat. Every sentence adds decision-relevant information, and there is no filler or redundancy.

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 is read-only and has an output schema, so the return values are documented elsewhere. Still, with 10 optional parameters and zero schema descriptions, the description could more explicitly state which inputs are monthly versus annual and whether the overhead should be passed as individual line items or a total.

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 0%, so the description must carry the semantic burden. It does map the main input categories: membership fee, annual pay goal, monthly overhead, and per-member cost, and implies that overhead parameters like rent and staff are monthly. However, it does not enumerate all ten parameters or clarify units for ambiguous ones like 'other' and 'supplies.'

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 tool's function with a specific question: 'How many members a direct primary care practice needs to break even.' It also lists inputs and outputs, making the purpose unambiguous. However, it does not explicitly distinguish itself from sibling tools like dpc_startup_cost, which is a similar financial calculator.

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 intended use case is implied by the description—break-even planning for a DPC practice—but there is no explicit 'when to use this' guidance or mention of alternatives. The default-value note is useful but does not help an agent choose between this and other calculator tools.

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