End period date

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

Annotations already declare readOnlyHint and openWorldHint, so the read-only nature is known. The description adds the return format and the notion of period abbreviations, but it does not disclose behavior for invalid periods, missing docs, or how 'accounting' is resolved. No contradiction with 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 description is a single, front-loaded sentence with no filler. It states the action, the output format, and the input scope efficiently, earning its place without repeating annotation or schema content.

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 read-only tool with well-documented parameters and readOnlyHint, the description is nearly complete. Minor ambiguity remains about the phrase 'of the accounting' — it likely means the accounting period but is not explicitly stated, preventing a perfect score.

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?

The input schema covers both parameters with 100% coverage, including a default mechanism for doc and an example for period. The description only reinforces the idea of a 'period abbreviation' without adding meaning beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Return'), names the resource ('end date'), and specifies the output format (YYYY-MM-DD). It clearly distinguishes from the sibling tool banana_start_period by focusing on the end date, and scopes the input to an accounting period or period abbreviation.

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 implies use when needing the closing date of an accounting period or abbreviation, but it gives no explicit guidance on when to prefer this tool over alternatives such as banana_start_period. No exclusions or alternative tool names are mentioned.

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