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

Annotations already cover read-only, non-destructive and idempotent behavior, so the description only needs to add context — and it does, by clarifying that no purchase or wallet debit occurs. It does not say whether an unsupported meter returns a false flag or raises an error, which is the remaining behavioral gap.

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 short sentences, usage constraint first, negation second. Nothing wasted and no repetition of the title.

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 explaining return values is not required, and the pre-requisite ordering is fully stated. Only the failure-mode semantics (error vs. negative result) are left implicit, which is minor for a one-parameter read 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?

Single parameter with 100% schema description coverage, so the defensive baseline applies. The description only restates that the input is a prepaid meter number and adds no format or normalization detail beyond the schema.

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 and resource ('check whether a prepaid electricity meter is supported') and scopes it as a pre-flight validation, which cleanly separates it from the create_/get_ siblings. An agent can identify the tool's job without opening the 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?

Explicitly says to use it 'before create_electricity_order', naming the sibling and the ordering dependency. It also states the negative case ('does not buy electricity or spend wallet funds'), removing the main ambiguity in a wallet-spending API surface.

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