fuel_price_guide

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds real behavioral context the annotations cannot: it discloses the content dimensions (mechanism explanation, latest September 2026 snapshot, August and July historical comparisons), which tells the agent exactly how fresh and how deep the data is.

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?

A single sentence, front-loaded with the core resource and units before the parenthetical detail. The parenthetical grade list and the three content facets are dense but all earn their place; only minor polish (splitting mechanism from snapshot/history) would improve it.

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 formatting need not be described, and the description covers the full scope of what is returned. For a zero-parameter, read-only guide tool it is essentially complete; the only gap is any statement of update cadence or data staleness beyond the September 2026 date.

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?

The tool takes zero parameters, so the schema imposes no semantic burden and the baseline is 4. The description correctly does not invent parameters, and its content list implicitly communicates that the response is fixed-scope rather than filterable.

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 names a specific resource (monthly UAE fuel prices in AED per litre) and enumerates exactly what is covered: the four fuel grades, the Fuel Price Committee mechanism, a dated snapshot, and historical comparisons. No sibling tool in this catalog returns fuel price data, so an agent can identify it immediately without opening a 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?

Usage is only implied by the content: an agent can infer it should call this for UAE fuel price questions. There is no explicit when-to-use statement, no exclusions, and no mention of whether the snapshot is stale relative to current months. However, no sibling tool overlaps this domain, so the absence of routing guidance is less damaging than it would otherwise be.

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