mess_list_extras

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds useful behavioral context: it explains that extras with the same ID may appear across multiple meals (a data characteristic not captured in annotations). It doesn't mention authentication requirements, rate limits, or pagination behavior.

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 well-structured with purpose statement, behavioral note, Args, and Returns sections. It's appropriately sized but could be slightly more concise by integrating the behavioral note into the main purpose statement.

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?

Given the tool has comprehensive annotations (read-only, non-destructive, idempotent, open-world) and an output schema (Returns section describes JSON array structure), the description provides adequate context. It covers parameters and basic behavior, though could better explain authentication requirements given the auth_key/session parameters.

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%, but the description's Args section documents all 3 parameters (meal, date, mess ID) with basic semantics. However, it doesn't explain the relationship between auth_key/session parameters (nested in params object) and the tool's authentication behavior, leaving gaps despite the schema having no descriptions.

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 clearly states the specific action ('List available extra items'), target resource ('for a meal on a date'), and scope ('Some extras may be available across multiple meals'). It distinguishes from siblings like mess_get_extras_in_range (range-based) and mess_get_registered_extras (user-specific).

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 usage for listing extras for a specific meal/date, but doesn't explicitly state when to use this versus alternatives like mess_get_extras_in_range (date range) or mess_get_registered_extras (user's registered extras). No explicit exclusions or prerequisites are mentioned.

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