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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description goes beyond them by disclosing the return shape (a table, notable differences, and a head-to-head page when one exists) — useful since there is no output schema.

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 sentences, zero filler. The core action and its constraints come first, with the return-value note following — appropriately front-loaded for a one-parameter tool.

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, single-parameter, read-only tool with full schema coverage and no output schema, the description covers the action, the input range, and the return contents. Minor gaps remain: no note on behavior when a slug is invalid or unmatched.

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 100% and the single 'tools' parameter is fully documented with type, bounds, and an example. The description's 'by slug or name' restates what the schema already says, adding no syntax or format detail beyond it, so the baseline 3 applies.

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 and resource ('Compare tools side by side') with the input form (slug or name) and cardinality (2 to 4). An agent can immediately tell this is a multi-tool comparison rather than a lookup, but the description never names the siblings it differs from (get_tool, search_tools).

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-4 constraint implies a multi-tool comparison scenario, and the mention of the head-to-head page hints at intended use, but there is no explicit 'use this when...' or 'use get_tool instead for a single tool' guidance. Usage is inferable rather than stated.

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