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

Well beyond the annotations, it discloses cost ('Spends nothing'), the exact credit threshold (20 sats), that sub-threshold calls are recorded but uncredited, that credits are not cash, and a rate limit ('credits pause after a few per account'). These are precisely the side-effect, cost, and throttling facts an agent needs for a non-idempotent write.

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 sentences, front-loaded with the purpose and the cost fact, then the credit mechanics. No filler, no repetition of schema or annotation content, and each sentence conveys a distinct fact.

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?

An output schema exists so return values need no explanation, and the annotations cover the mutation profile (readOnly=false, idempotent=false). What remains — cost, credit rules, and throttling — is fully stated, leaving no meaningful gap for an agent calling this tool.

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% across all 7 parameters, so each field (order_id, worked, matched_schema, useful, latency_ok, line, note) is already documented in the schema. The description adds no parameter-level detail, which matches the baseline 3 when the schema carries the semantics.

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 first sentence states a specific verb and resource ('Report how a paid call went'), and the surrounding sentences scope it to post-call feedback tied to an order. It is clear without opening the schema, though it never names the nearest sibling (claim_failed_call) to disambiguate the two reporting paths.

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 useful qualifying context for when a credit applies (>= 20 sats) versus when a call is merely recorded, and states it 'spends nothing', which implies it is safe to call freely. It stops short of explicit when-to-use/when-not guidance or naming an alternative tool, so the routing is left partly to inference.

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