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

The annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered. The description adds value beyond them by disclosing the return payload: content_json with pricing, recent moves, positioning, displacement signals, and when-to-choose, plus metadata. Minor gap: no mention of behavior for an unknown or unpublished slug.

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?

Three tight sentences, front-loaded with the usage trigger, then the operation, then the return shape. No redundant restatement of the tool name or filler.

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 one required parameter, no output schema, and annotations covering the safety profile, the description is nearly sufficient — it even enumerates the return contents. The only missing piece is what happens on a missing/invalid slug, which matters for a slug-keyed fetch.

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 100% and the schema already documents the single slug parameter, including its origin (list_comparisons). The description repeats that origin but adds no new syntax, format, or constraint detail, 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: fetches the full structured body of one published competitor comparison by slug. It is clearly distinguishable from list_comparisons (which enumerates slugs) and from the other get_* siblings, which cover different resources.

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?

"Use when the user wants the full head-to-head detail for one published comparison" gives an explicit trigger, and the parenthetical routes the agent through list_comparisons first to obtain the slug. It doesn't explicitly state the inverse case (use list_comparisons for summaries/listing), but the sequencing implication is strong.

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