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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The phrase 'computed insights' hints that the tool does more than return raw records, but it never says what those insights are or how the comparison is derived, and no invalid-slug behavior is 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?

A single front-loaded sentence with no filler. Brevity is a virtue here, though it comes at the cost of any guidance beyond the core action.

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?

With an output schema and full annotations, the description needn't explain return values or safety. Still, for a comparison tool the description omits what dimensions are compared and how to handle unknown or duplicate slugs, leaving meaningful gaps for 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?

There is one parameter with 0% schema description coverage; the schema only says 'array of strings'. The description clarifies that the entries are tool identifiers ('tools') and that 2-4 are required — though the count range merely restates minItems/maxItems already in the schema. Adequate but thin for a zero-coverage parameter.

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 ('tools') plus the accepted cardinality ('2 to 4 ... side by side'). It clearly differs from single-tool siblings like get_tool and from search_tools, though it never names an alternative 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?

Usage is only implied by the verb — nothing says when to prefer this over get_tool, get_alternatives, or recommend_tools, nor what precondition (e.g. needing multiple known slugs) makes it the right choice. An agent must infer the routing decision entirely.

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