Update or create a phone provisionings custom configuration key

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

Annotations already declare write (readOnlyHint=false), idempotentHint=true, destructiveHint=false and openWorldHint=true; the description only restates 'update or create' consistently with them and adds no new behavioral context. It says nothing about what happens to unspecified existing configuration entries on merge, permission requirements, or scope of the open-world effect.

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 first sentence is appropriately front-loaded and wastes nothing. The second sentence is a bare HTTP path that largely duplicates the tool name, so the definition is short but not maximally informative per sentence.

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 mutating tool taking an untyped nested 'configurations' object with no output schema needs more: what a 'custom configuration key' is, the expected key/value structure, and what the response returns. Annotations cover the safety profile, but the description leaves the core data contract unexplained.

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 baseline is 3. The description adds nothing about what the 'id' refers to (provisioning id) or what shape the free-form 'configurations' object must take, which is the one genuinely ambiguous parameter.

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?

Names a specific verb pair (update or create) and a specific resource (a phone provisioning's custom configuration key), which is enough to distinguish it from the sibling read (get_provisioning_custom_configurations) and delete (delete_provisioning_custom_configuration) tools. It does not explicitly call out those siblings, so it stops short of a 5.

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?

There is no explicit guidance on when to use this upsert versus create_provisioning/update_provisioning or the custom-configuration delete/get siblings. The only usage signal is the '(PUT /provisionings/{id}/custom_configurations)' path, which implies idempotent upsert semantics but is left for the agent to infer.

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