Custom Attributes: Add a new custom attribute

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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the description's job is lighter. It adds real value beyond them: the auth header required, the exact request path, the accepted body fields, and the note that Persian/Arabic-Indic text and digits are sent unchanged, which matters for data integrity.

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?

It is front-loaded with the action, then gives endpoint, auth, body fields and the encoding caveat in a compact block. No filler sentences, though the field list slightly duplicates the schema.

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 creation tool with 8 parameters, a nested extra_body object and no output schema, the description supplies the auth method, the endpoint, the mappable body fields and the escape hatch for extra fields. It does not describe the response or error behavior, which is the main remaining gap.

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 100%, so the schema already documents every parameter including the display-type and model enumerations. The description restates the body field names but adds no semantics beyond that, apart from the language/digit handling note; baseline 3 applies.

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 opens with a specific verb+resource ('Add a new custom attribute') and includes the concrete endpoint, so the agent knows exactly what is created. It is distinguishable from siblings like list/get/update/remove_custom_attribute, though it never names them explicitly.

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?

Usage is implied by 'Add a new' versus the sibling update/remove tools, but there is no explicit statement of when to prefer this tool over gapify_update_custom_attribute or what prerequisites exist. The requirement of a User API key is stated, which helps a little.

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