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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description goes well beyond by stating a connected Aurgus account is required, that cadences can be set or changed later, and that supplying settlement_approver_email causes Aurgus to hold every settlement until a one-time email approval lands. Those are real behavioral consequences an agent cannot infer from structured fields.

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?

Front-loaded with the purpose, then a numbered enumeration of the two decisions the user must be asked. Slightly long because it re-lists enum values already in the schema, but each sentence (account requirement, one-or-both, change-later) carries information.

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 non-destructive 4-parameter mutation with no output schema, the description covers prerequisites, partial updates, and the approval side effect. It does not say what the tool returns or what happens with invalid combinations (e.g., 'threshold' without a threshold value), leaving a small gap.

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 100%, so baseline is 3; the description earns a bump by glossing the cadence values with meaning the schema mostly omits ('realtime as sales land', 'threshold when a dollar threshold is hit') and by stating that only one cadence need be passed. It adds nothing about settlement_approver_email beyond the schema, so not a 5.

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?

Opens with a specific verb+resource pair: 'Set how often an agreement ACCRUES and SETTLES.' This clearly separates it from execution-oriented siblings like settle, close_agreement, and compute_close, which act on money movement rather than configuring cadence.

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 frames the usage context: 'Ask the user these when setting an agreement up (or to change them later)' and clarifies 'you can set one or both.' It does not name a sibling alternative (e.g., edit_agreement_rates) for callers wondering where related edits belong, so it stops short of full when/when-not routing.

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