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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered; the description adds genuinely new behavior by saying the values are read from the contract, that fees are flat and never a percentage of the amount, and that limit validation only happens when an amount is passed. It does not describe output shape or error behavior, but no output schema exists to lean on, keeping it just short of a 5.

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 dense sentences, front-loaded with the core output, then the amount-dependent behavior, then the flat-fee caveat. Slight redundancy in re-listing the six enum values that the schema already enumerates, but nothing else is wasted.

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 two-parameter read tool with no output schema, the description covers what each return value is (creation fee, result fee, approved total, in-limits flag) and where the numbers come from. Only the exact field names/shape of the response remain unstated, which is a minor 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 the baseline is 3, but the description adds real semantic value beyond the schema: it explains that the kind selects which fee tiers apply (result fee only for SPORTS and MARKET) and that the optional amount is what unlocks the approved-total and limit-check outputs. The enum list in the description largely repeats the schema.

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 computation ('The fee for an if-so payment of one condition kind') and enumerates exactly what is returned: flat creation fee, flat result fee for SPORTS and MARKET, and, with an amount, the approved total and limit check. That is a precise verb+resource statement an agent can distinguish from get/quote siblings.

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 clearly frames the two modes: calling with only a kind returns base fees, while supplying an amount additionally returns the sender's approved total and whether the amount is within contract limits. It also points to ifso_version as the source of the same numbers and to ifso_list_conditions for the kind vocabulary, though it never states an explicit when-not or alternative tool to use instead.

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