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

Annotations already indicate idempotentHint=true and destructiveHint=false. The description adds 'on a live event' implying real-time effect, but does not disclose additional behavioral aspects like potential side effects, rate limits, or conflict handling. This is adequate but not rich.

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 two sentences: the first efficiently lists editable fields, the second states required parameters and condition. Every word carries weight; no redundancy or superfluous information.

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's complexity (10 parameters, no output schema), the description covers purpose, requirements, and editable fields well. It does not describe the return value or what happens on success/failure, which is a minor gap. However, it is sufficient for an agent to invoke the tool correctly.

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?

With schema description coverage at 0%, the description compensates by enumerating many editable fields: code, discount, max uses, start/expiry, applicable classes, enable/disable. It clarifies that event_id and promo_code_id are required. However, it omits details about discount_type (enum) and null allowed for dates. Overall, it adds significant value beyond the bare 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 clearly states 'Edit a promo code on a live event' and lists specific fields (code, discount, max uses, start/expiry, applicable classes, enable/disable). The verb 'Edit' combined with the resource 'promo code' makes the action unambiguous, and it distinguishes from sibling tools like create_promo_code.

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 specifies prerequisites: 'Requires event_id + promo_code_id; you must be a host.' This clearly indicates when to use the tool. It does not explicitly state when not to use it or name alternatives, but the context of sibling tools (e.g., create_promo_code) provides implicit guidance.

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