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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safe, bounded-read nature is covered. The description adds provenance context (prices come from Régie Essence Québec), but discloses nothing further about result size, ordering, or freshness of the municipality list.

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 sentences with the core function front-loaded and no filler. The trailing sentence on price provenance is context rather than invocation-critical information, so it is slightly beyond strict minimum.

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 zero parameters and no output schema, the description does the work of telling the agent what comes back (municipalities plus their citySlug). It is nearly complete, needing only a note on how the list relates to search_locations.

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 baseline is 4. The description correctly adds no parameter syntax and instead documents the returned citySlug identifier, which is the relevant semantic detail for a parameterless tool.

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 ('List every Quebec municipality tracked by Gas Quebec') and clarifies the key output artifact, the citySlug used by the other tools. It does not explicitly differentiate itself from the closest sibling, search_locations, so it falls short of a 5.

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: the mention that citySlug is 'used by the other tools' hints this is the discovery/lookup step before calling get_city_prices or find_cheapest_stations. There is no explicit when-to-use statement, no exclusion, and no guidance on how it relates to search_locations.

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