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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description doesn't need to cover safety. It adds useful content boundaries (cargo/vehicles, no prices) and hints at output structure ('a page for each'), but doesn't go much deeper.

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?

Three short sentences, front-loaded with the core action and resource, followed by optional-filter guidance and a useful exclusion. Every sentence earns its place with no filler.

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?

For a simple read-only tool with one optional parameter and no output schema, the description covers the content returned and the filtering option. 'A page for each' is slightly vague, but not enough to block correct invocation.

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%, so the schema already documents the 'filtre' parameter. The description adds helpful examples like 'Mali', 'Bamako', and 'Abidjan', but this reinforces rather than substantially extends 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?

The description names a specific resource ('road corridors GraceRoad serves'), a concrete action ('Lists'), and the content included ('typical cargo and vehicles'). This clearly distinguishes it from sibling tools like graceroad_preparer_demande and graceroad_presentation.

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?

It gives clear context for use: enumerate corridors, optionally filter by country or city, and it explicitly notes the result 'Contains no prices.' It doesn't name sibling alternatives or state when not to use them, so it stops short of a 5.

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