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

Annotations declare it is a non-destructive mutation, and the description adds two useful traits: patch semantics (only sent fields change) and that the call echoes the updated value. It does not mention permissions, side effects on bookings, or validation failures.

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?

Two tight clauses, front-loaded with the action, then the patch rule and the workflow hint. Minimal waste.

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?

A 15-parameter mutation tool with no output schema and no annotations coverage of field-specific behavior. The description covers patch semantics and return of current value but omits the shape of that returned value and any validation rules.

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 coverage is 73%, so most parameters are self-documented. The description adds nothing about individual field semantics; the patch note applies to all fields but the schema already implies optionality via non-required fields.

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?

Clear verb+resource (Change a discount) and describes the partial-update semantics ('only the fields sent change'), which distinguishes it from create_discount/delete_discount. No explicit naming of siblings, but the CRUD role is unambiguous.

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?

Gives a concrete workflow instruction: 'Read the current value with its read tool first' (list_discounts/get). Does not state when not to use it, e.g. vs create_discount for new discounts, but the guidance is actionable.

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