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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful context beyond those annotations: field-by-field comparison, no commercial obligation, and Risk R0/PUBLIC classification. No contradiction exists, though return behavior is not described.

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 short sentences with no filler. The primary behavior and constraints are front-loaded, and the additional risk/commercial context is compact and informative.

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 one-parameter, read-only comparison tool, the annotations cover the safety profile and the description covers scope and constraints. The main gap is lack of explicit output/return description, but no output schema exists and 'field by field' provides a reasonable expectation.

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 0%, so the description must compensate. It clarifies that the slugs refer to declared service contracts and constrains the count to 2-4, but it does not name the parameter or explain slug semantics beyond the schema's regex and min/max constraints. Partial compensation only.

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 action (compare field by field), an exact input range (two to four), and an explicit non-goal (no ranking score). This clearly distinguishes it from directory/search or ranking siblings.

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 makes clear the operation is for comparing 2-4 declared contracts without ranking, so its appropriate use is implied. However, it does not name alternatives or exclusion conditions, leaving usage guidance implicit rather than explicit.

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