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

With no annotations, the description carries full burden. It discloses that missing facts return indeterminate and provides a disclaimer that it's not tax or filing advice. It also mentions pricing and payment flow. However, it does not describe side effects, authorization needs, or rate limits beyond cost. Behavioral traits beyond what is stated are missing.

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 somewhat lengthy due to pricing and payment details, but front-loads the purpose. It could be more concise by separating operational info (pricing) from functional description. Each sentence adds value, but the structure mixes core function with payment instructions.

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?

Given an output schema exists, the description does not need to explain return values. It covers credit types, fact requirements, and pricing. However, it lacks details on what 'auditable' means and the expected structure of the output. The description is adequate but not thorough for a tool with no annotations.

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 0%, so description must add meaning. It specifies that 'credit' can be '45Q, 45V, 45Y, 48E, or 45X' and that 'facts must contain the explicit credit-specific eligibility facts'. It also hints at 'payment_ref' in pricing. This adds significant value beyond the bare schema, though the structure of 'facts' remains vague.

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 purpose: 'Calculate an auditable tax-credit scenario.' It lists the specific credit types (45Q, 45V, 45Y, 48E, 45X), which distinguishes it from sibling tools like verify_tax_credit_result that handle verification. The verb 'Calculate' and resource 'tax-credit scenario' are precise.

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 notes that 'missing facts return indeterminate' and provides pricing and payment instructions, but lacks explicit guidance on when to use this tool vs siblings like get_rule_pack or verify_tax_credit_result. No 'when not to use' or alternative recommendations are given.

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