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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new context: gpu:true nodes always delegate to the browser, inputs are processed transiently and not retained, synthetic/anonymised inputs are required, and the call exports an AP2 artifact carrying execution_hash for chain provenance. That extra disclosure is substantive rather than a restatement of the annotations.

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 purpose is buried behind repeated infrastructure boilerplate ('OpenChainGraph compute node ... Deterministic OpenChainGraph compute node'), a verbatim restatement of the compute enum already in the schema, and a 64-character FV-status hash URL. The dangling list of 15 output field names at the end is unstructured, and the front-loaded content is process plumbing rather than what the tool does.

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?

With no output schema, the description does enumerate output fields and explain compute modes, privacy and provenance, which covers a lot. But it never explains what the returned flags actually mean (impairment_flag, incremental_cost_test_passed, renewal_treatment) or the semantics of the nested policy_parameters, leaving gaps for a compliance calculation of this complexity.

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 100%, so the parameter contract is already documented and the 3 baseline applies. The description adds a little meaning for policy_parameters through the expedient rule keyed on contract_term_months, but the other keys (renewal_cost, incremental_cost, impairment_indicators, renewal_commensurate, amortization_period_override_months) get no interpretation beyond their names.

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 standard and computation: 'ASC 340-40-25-4 practical expedient ... and full straight-line amortization schedules for longer-term capitalized incremental costs of obtaining a contract under ASC 606.' That is a concrete verb+resource and the ASC citation implicitly separates it from generic siblings like build_amortization_schedule or compute_deterministic_amortization_schedule, but no sibling is named outright, so it stops short of a 5.

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 states the decision rule ('contract_term_months <= 12 -> expense immediately, apply_expedient=true') and a prerequisite ('Consumes upstream artifacts from: art-266-reconcile-commission-statement'), which implies when it applies. However there is no explicit when-to-use/when-not guidance and no named alternative among the many amortization-related siblings.

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