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

With no annotations, the description does add some real behavioral context beyond the schema: 'Auth mode: paid' and the $0.003/call pricing over x402/MPP, which an agent needs to know before invoking. However, it says nothing about the validation result semantics (what a pass/fail looks like) or any error behavior, leaving the core behavior undisclosed.

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 bulk is machine-generated boilerplate — origin URL, hostname, brand, provider aliases, family key, endpoint — that is irrelevant to selecting or invoking the tool. The actual purpose sentence is buried in the middle under 'Summary' rather than front-loaded.

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?

There is no output schema and no annotations, so the description should explain what validation returns (valid/invalid, normalized value, control-digit detail), and it does not. For a tool whose entire value is a boolean-ish check, that omission leaves the agent guessing at the result shape.

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 0% and the single parameter is a bare 'value' string with no constraints. The description only indirectly implies that 'value' is an economic code; it adds no format, length, or digit rules to compensate for the schema gap.

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 Summary line gives a specific verb+resource: 'Validate an Iranian economic code (کد اقتصادی) with its control-digit check,' and the use cases reinforce the exact resource. It is distinguishable from sibling validators like iran_company_id and iran_national_id by naming the economic code, though that differentiation is only implicit.

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?

Three use cases (tax form validation, control-digit check, vendor tax identifier verification) give context for when to call it, but there is no guidance on when to prefer this over sibling Iran validators such as iran_company_id or iran_national_id, and no exclusions.

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