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

The description discloses the line-by-line output format and the specific rows compared, which goes beyond the readOnlyHint annotation. It also notes the three-service limit. However, it does not mention error behavior or any other side effects, but since it is read-only, the additional context is valuable.

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 description is front-loaded with the core purpose and then lists attributes; it is logical and without filler. It is somewhat long but each sentence adds value.

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?

The description lists comparison attributes, giving some idea of output, but relies on the website table reference without specifying the exact return format. It does not address optional parameters or error handling, which is a gap given no output schema.

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 only 20% (services only). The description mentions 'schedule' implying days and hours but does not define their semantics or units. It does not clarify city or transport parameters, failing to compensate for the low schema coverage.

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 clearly states that the tool compares two or three services in one city line by line, listing specific attributes (rate, income, schedule, etc.). This distinguishes it from sibling tools like find_services or calculate_income, which serve different purposes.

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 description implies use for side-by-side comparison of services but does not explicitly reference alternative tools or state when not to use it. The limitation of three services is a constraint, not a usage guideline. There is no explicit 'use this when' statement.

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