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

Annotations already declare this read-only, idempotent, closed-world and non-destructive, so safety is covered. The description adds two real facts: results are evidence-backed and objective, and only approved tools are eligible. It does not say what happens with unapproved or unknown identifiers, which matters for a closed-world tool.

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?

A single front-loaded sentence with no filler; each clause (range, eligibility, identifier forms, evidence-backed output) carries distinct information.

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 small two-parameter tool this covers the core call, but with no output schema the description should say more about the shape of the comparison result, and it omits the locale parameter and error behavior for ineligible IDs.

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 coverage is 0%, and the description compensates well for the required parameter by defining acceptable identifiers (UUID or canonical slug) and the 2-5 distinct-tool constraint, which the schema alone would only express as an untyped string array. It leaves the optional locale parameter entirely unexplained, which keeps it off a 5.

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 (compare) and resource (approved tools) plus the identifying key (UUID or canonical slug), which is enough to separate it from get_tool and search_tools. It stops short of explicitly naming those siblings as alternatives, so it is clear rather than exemplary.

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 2-to-5 and 'approved tools' constraints imply the comparison use case, but there is no explicit when-to-use or when-not-to-use guidance, and no routing such as 'use get_tool for a single tool'. Usage must be inferred from the siblings.

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