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

With no annotations, description carries full burden. It discloses restrictions, use cases, and idempotent behavior (returns success with credits_granted=0 if already credited). Lacks explicit statement that it is a write operation, but the context implies ledger mutation.

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?

Description is concise and well-structured: bold lead, then paragraph, use cases, idempotency note. Every sentence adds value, no fluff. Front-loaded with purpose.

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?

Given medium complexity, no annotations, and presence of output schema, the description fully covers purpose, who can use it, when to use it, and key behavior (idempotency). It is sufficient for an agent to decide and invoke correctly.

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 baseline 3. Description does not add parameter-specific information beyond the schema; it mentions no parameter names or constraints.

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 'Credit a patron's ledger from a BTCPay-settled invoice' with a specific verb and resource. It distinguishes from siblings like cypher_purchase_credits and cypher_check_payment by clarifying it is for operator-only manual crediting after infrastructure incidents.

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?

Explicitly says RESTRICTED to operator, defines when to use (e.g., cold-start vault races, ncred hiccups), and when not (patrons must escalate). Also notes idempotency, guiding agents on safe invocation.

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