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

The description adds useful behavioral detail beyond the readOnlyHint annotation: it returns the menu for the active school, accepts either date or month, and defaults to today's menu when neither is provided. It also explicitly says 'Read-only,' which aligns with the annotations. No contradictions exist.

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 three short sentences and front-loads the core purpose. Every sentence adds useful information: what it returns, the parameter options, the default, the read-only nature, and the intended downstream use. No filler or redundancy.

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 two optional parameters and an output schema, the description is fully sufficient. It covers the active-school context, parameter selection behavior, default behavior, and intended use case. The output schema handles return-value details, so nothing critical is missing.

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?

Even though the schema already documents the two optional parameters and their formats, the description adds the important semantics that they are alternatives and that omitting both yields today's menu. This clarifies mutual exclusivity and default behavior, adding value beyond the schema.

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 verb and resource: 'Returns the daily lunch menu for the user's active school.' It also connects to a concrete downstream use ('find menu_item_id values for order_lunch'), which makes its role among the sibling tools clear. The daily-menu resource is distinct from monthly orders, events, wallet, and user-info tools.

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 clearly explains when the tool is useful: to retrieve menu items and get menu_item_id values for ordering lunch. It also covers the optional input behavior with date/month/today defaults. It does not explicitly state when not to use it or name alternatives, so it stops short of a 5.

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