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

With no annotations, the description carries full behavioral burden. It usefully discloses the default behavior (July start) and a commercial constraint (5 free trial calls per signed wallet), which is real context, but it says nothing about the return shape or error behavior for non-July configurations.

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?

One front-loaded sentence states purpose, inputs, and default; the trailing trial-call note is a minor but informative addition. No redundant restatement of the tool name beyond the leading label.

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 simple two-parameter computation with no output schema and no annotations, the description is adequate: purpose and default are covered. It falls short on input formats and on what the returned fiscal-year number looks like, which matters since nothing else documents it.

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%, so the description must compensate. It does name both parameters conceptually ("a date" and "a configurable first month") and reveals the default first month, but gives no format hints for the date string or the expected startMonth representation (name vs number).

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?

States a specific verb and resource ("Computes the fiscal year number") plus the operating scope ("for a date and a configurable first month"). This is clearly distinguishable from the sibling x402-fiscal-quarter because it names the fiscal-year output explicitly.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as x402-fiscal-quarter or the many other date tools. The reader must infer the use case entirely from the purpose statement.

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