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

Annotations already declare readOnlyHint=false and destructiveHint=false; the description adds useful behavioral context by marking this as a WRITE operation and noting that it changes the proposal's price. It also explains the fee calculation behavior, though it does not cover permissions, side effects on existing fees, or response behavior.

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 WRITE marker and core action, followed by the essential pricing rule and endpoint. Every sentence contributes useful information without repetition or filler.

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 mutation tool with annotations and no output schema, the description covers the key behavior: it is a write, it affects proposal price, and fee-type-specific amount semantics. It could be more complete by mentioning custom fees, optional items, and error or permission behavior, but it is sufficient for correct invocation in most cases.

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 coverage is 56%, and the description compensates for key gaps by explaining that fixed fees treat amount as a total while hourly, monthly, and yearly fees treat amount as per-unit and require quantity. It leaves custom fee behavior and several optional parameters such as category and optional unaddressed, but the critical pricing semantics are clarified.

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 uses a specific verb and resource: 'add a fee line to a proposal,' and adds scope with 'it changes the proposal's price.' It also includes the write nature and endpoint, making it clearly distinguishable from read/list fee tools.

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?

It gives clear usage context for adding a new proposal fee and explains how fee type affects amount and quantity handling. It does not explicitly name alternatives like update_proposal_fee or create_fee, so the when-not guidance is implicit rather than explicit.

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