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

Annotations already declare this as a read-only, idempotent, open-world, non-destructive lookup. The description adds meaningful behavioral context beyond annotations: it does not run an expiry engine, unpublished months are returned as unknown with a product-page link, and official exchange notices take precedence.

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 compact and front-loaded, stating the core output first and then adding key caveats about the expiry engine, unknown months, and official-notice precedence. Every sentence adds useful information without repetition.

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 two-parameter read-only lookup with no output schema, the description is largely complete: it covers purpose, default month behavior, unknown-month handling, and precedence caveats. The main remaining gap is the product parameter format, which the schema pattern shows but does not semantically explain.

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 carry parameter meaning. It clearly defines the optional month as YYYYMM delivery month with a default of the next published month, but the required product parameter is only described generically as 'a product' without explaining the expected product code format.

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 states a specific resource and output: published last-trading and first-notice dates for a product, optionally filtered by delivery month. It is clear what the tool returns, though it does not explicitly distinguish itself from sibling tools such as next_closure or recent_notices.

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 the month parameter defaults to the next published month and that unpublished months are unknown, which helps set expectations. However, it does not explicitly say when to use this tool instead of alternatives like next_closure or recent_notices.

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