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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the description doesn't need to restate mutation. It adds valuable context: the exact endpoint, the escrow-locking behavior, the x402-shaped receipt format, the network (afg-mock-ledger), and the TEST MONEY ONLY warning. This goes beyond what annotations provide.

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?

Three sentences with zero waste. The core action and endpoint are front-loaded, followed by the precondition, return format, and the critical test-money warning. Every sentence 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 mutation tool with no output schema, the description covers the action, endpoint, precondition, return shape, and safety warning. It doesn't explain the two wallet modes (session vs bring-your-own-wallet) in the description, but the schema covers those parameters thoroughly, so the gap is minor.

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 schema already documents all parameters. The description adds the key semantic that the body is empty ('body {}') and that the tool returns a receipt, which helps an agent understand the call shape. It doesn't deeply explain the signed_request flow, but the schema covers that.

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 ('locks the price in escrow'), the resource (job on the MOCK ledger), the exact endpoint (POST /v1/jobs/{job_id}/fund), and the required precondition (state AGREED). It clearly distinguishes this from siblings like afg_post_job or afg_submit by focusing on the funding/escrow step.

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 explicitly states the precondition 'Needs state AGREED' and the test-only context, which tells an agent when this tool is appropriate. It doesn't explicitly name alternatives or exclusions, but the precondition and mock-ledger emphasis provide clear usage context.

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