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

With no annotations, the description carries the full burden and does substantial work: it discloses the 1 CRD charge per call, that the charge applies even to rejected calls, that a 429 RATE_LIMITED is free, and that errors return a request_id to quote to support. It stops short of describing the successful response body and does not state idempotency or retry behavior.

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?

Front-loaded with the action, then value constraints, then cross-cutting cost and error behavior. Every sentence contributes a fact an agent would otherwise have to discover by failing a call; there is no filler.

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 an 11-parameter mutation with no annotations and no output schema, this covers the high-risk unknowns (cost, error shape, id semantics). The gap is the success response: with no output schema, the description should say what a created tier returns so the agent knows what to do with the result.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning the schema lacks: the price band (0 or 0.50–1.00 per credit, which is not expressible in the schema), the equivalence of omitting credit_type_ids and passing [], and the rejection of malformed or foreign ids.

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?

Opens with a specific verb+resource: 'Create a pricing tier'. Combined with the name, an agent can distinguish it cleanly from delete_pricing_tier, update_pricing_tier, and list_pricing_tiers without opening a schema.

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 only implied by the domain (creating a sellable credit tier). There is no explicit statement of when to use this versus update_pricing_tier or when a tier is the right model, and no stated prerequisites beyond the value constraints.

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