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

Annotations already establish readOnly, idempotent, non-destructive, open-world behavior, and the description adds real context beyond that: latest benchmarks may be futures and must never be relabeled spot or settlement, plus the tool is usable without signup. What is missing is any mention of error behavior for unsupported benchmarks or staleness bounds.

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?

Front-loaded with the core action, then the handling constraints, then access notes — a sensible ordering with little waste. The 'Demo is available without signup' sentence is the weakest, though it does convey an auth fact an agent cannot get elsewhere.

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?

With no output schema, the description compensates by enumerating the fields an agent should expect and preserve (dataset name, currency, unit, source, freshness), which is the right level of detail for a single-parameter read. Only error and freshness-boundary behavior remain unspecified.

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 0%, so the description must carry parameter meaning, and it only says the benchmark is 'supported' — the enum values (BRENT_CRUDE_USD, WTI_USD, etc.) are self-explanatory but receive no elaboration in the description. The description does not explain selection criteria between the six benchmarks or what units each returns.

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: 'Read one supported latest energy benchmark,' which tells an agent it returns a single benchmark value rather than a series or comparison. It falls short of 5 because it never distinguishes itself from the sibling energy_get_latest, whose name implies a very similar capability.

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?

Usage is implied by 'one supported' benchmark and the instruction to preserve dataset name, currency, unit and source/freshness fields, which is genuinely useful handling guidance. However, there is no statement of when to prefer this over energy_get_latest, energy_history, or energy_compare, and no failure conditions are given.

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