Create a trunk

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

Annotations indicate this is not read-only, not idempotent, and not destructive. The description adds valuable context: it enforces account-level constraints, capacity 0 disables direction, and lists possible error codes. This goes beyond the annotations, though it could mention persistence or side effects more explicitly.

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 highly concise: two sentences covering the main action, a crucial usage hint, a behavioral note, and a list of error codes. No unnecessary words; front-loaded with the primary purpose.

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 (9 parameters, nested objects), the description covers the core behavioral aspects, includes error handling, and mentions prerequisites. However, it does not describe the return value (e.g., the created trunk object or ID), which would be helpful since no output schema exists.

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?

The input schema already includes descriptions for all 9 parameters (100% coverage). The description restates some of this (e.g., capacity 0 meaning disabled), but does not add substantial new semantic value beyond what the schema provides. Baseline 3 is appropriate.

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 verb 'Create' and the resource 'a new trunk group on your account.' It effectively distinguishes this tool from sibling tools like trunk_delete, trunk_update, and trunk_list by specifying that this is for creation.

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 provides a prerequisite check ('check acct_get_capacity first') and explains the implication of setting capacity to 0. However, it does not explicitly state when not to use this tool or directly compare to alternatives, which would elevate it to a 5.

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