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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds real value beyond them: the policy check, credential injection by Regent, the fact the key never reaches the agent, and the audit trail (reinforced by the intent param). It does not mention rate limits or error behavior, so it stops short of a 5.

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?

Two sentences, no filler, with the core purpose and method restriction front-loaded and the safety guarantee ('Nothing is changed and no money moves') closing it out. Every clause earns its place.

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 read-only proxy tool with full annotation coverage and no output schema, the description supplies what an agent needs: the base URL, allowed methods, credential-handling model and audit behavior. The one gap is that it never distinguishes this tool from the other *_read siblings in the set.

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 80% and the schema already documents path, facts, intent and user_token. The description only touches the method constraint (GET/HEAD/OPTIONS) and adds no format or semantics for the remaining parameters, so it sits at the baseline for well-covered schemas.

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?

States a specific verb (read) against a specific resource (https://api.stripe.com) with an explicit method constraint (GET, HEAD or OPTIONS only), which cleanly separates it from the write-oriented 'stripe_demo' sibling. It never actually names the write sibling or any other tool, so the differentiation is inferable rather than explicit.

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 method enumeration ('GET, HEAD or OPTIONS only') implies this is for non-mutating requests and that mutations belong elsewhere, but the description never says when to pick this over stripe_demo or the other *_read siblings. Usage is implied by the read-only constraint rather than stated.

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