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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds one genuinely useful behavioral detail: only 'active' skills are returned, and ids are included. The trailing 'GetSkills.' fragment adds nothing.

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?

The core sentence is front-loaded and efficient, but the dangling 'GetSkills.' is a meaningless restatement of the name that adds noise without information. Removing it would make this a clean two-clause description.

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, zero-parameter, read-only list tool with full annotation coverage, the description supplies what an agent needs: what is returned (skill names plus ids) and the 'active' filter. Lack of an output schema is mitigated by naming the fields returned.

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 there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies a no-argument enumeration.

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 resource and scope: 'the master list of active driver skills ... with ids', plus a concrete example (HAZMAT). This distinguishes it in spirit from the per-driver sibling ecourier_get_driver_skills, though it never names that sibling explicitly.

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?

The word 'master' implies an unfiltered enumeration, which implicitly contrasts with ecourier_get_driver_skills, but the description never states when to use this tool versus that one. Usage must be inferred from the word 'master' alone.

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