Billing Plans Update

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

Annotations already declare readOnly=false, idempotent=true, and destructive=false, so the mutation semantics are covered. The description adds genuinely useful operational context — the write_plans scope requirement and the 2025-03 API version — but says nothing about partial-update behavior or what happens to omitted fields on a PATCH.

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?

Five short lines, zero filler, with the action stated first and the endpoint/scope/version metadata trailing. Every line carries distinct information an agent can act on.

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 mutation tool with no output schema, the description covers the auth scope and API version but leaves the most consequential unknown unaddressed: which fields the free-form 'plan' object accepts and whether the update is partial or full. An agent can invoke it but cannot construct a correct body without outside knowledge.

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 both plan_id and plan. The description adds the {plan_id} path binding and the PATCH method, which clarifies how plan_id is used, but the free-form 'plan' object remains opaque in both places. Baseline 3 plus the path-binding detail lands at 4.

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 states a specific verb and resource ('Update an app billing plan'), which cleanly separates it from its siblings tiendanube_billing_plans_create and tiendanube_billing_plans_delete. It stops short of naming those siblings explicitly, so it lacks the differentiation language a 5 would require.

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 gives the HTTP verb, path, and required scope, which implies when the tool applies, but never states the conditions under which an agent should update versus create or delete a plan. Usage is therefore inferable rather than explicit.

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