register_extra

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

With no annotations, the description carries the full behavioral burden. It discloses that this is a booking/mutation action, states the prerequisite, and documents API-key fallback. However, it does not mention what happens on duplicate bookings, whether the action is reversible, or what errors/side effects to expect. The core behavior is visible, but post-condition and failure behavior are under-specified.

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: a one-line purpose, a single prerequisite, and a clean Args list. Important constraints are front-loaded or clearly grouped. Nothing extraneous is included.

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 five-parameter tool with no annotations, the description covers all inputs and the one critical prerequisite, and an output schema exists so return values need not be documented. It does not address availability/duplicate edge cases or explicit success/failure behavior, but those are largely inferable from 'book' and list_available_extras. Overall it is sufficient for correct invocation.

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 Args list documents every parameter with concrete semantics: extra_id's source, date format, enumerated meal_type values, mess purpose, and api_key fallback. This fully compensates for the bare schema and adds normative value. No parameter is left unexplained.

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 opening line, 'Book an extra item for a meal,' states a specific verb and resource. It clearly distinguishes this tool from register_meal and the other extra-management siblings, and the prerequisite sentence further clarifies its role. The name alone is vague, but the description removes that ambiguity.

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 explicitly states that a regular registration for the same mess and meal must exist before booking extras, which is the key usage condition. It also points to list_available_extras as the source for valid extra_id values. It does not explicitly name when to prefer other siblings, but the usage context is clear.

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