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

No annotations are provided, so the description carries the full burden. It discloses that this is a broad read of every runnable engine and what fields come back, which signals a safe, non-mutating catalog call, but it says nothing about filtering behavior, result size, or pagination for large catalogs. Adequate but thin for a tool with zero annotation coverage.

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 with the resource listed first and the usage guidance second, which is the right front-loading. The long parenthetical of compute categories is the only drag, but each item serves as a realistic trigger example rather than 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 no output schema, the description helpfully enumerates the returned fields (id, question, category), and the 1-param, non-nested schema makes the rest self-explanatory. It stops short of explaining the natural next step (feed an id into describe_engine/run_engine), leaving that to inference from 'call this first'.

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 optional 'category' filter is fully documented in the schema, including its fuzzy matching against category/id/skill title and summary. The description adds no parameter-level detail beyond the schema, so the baseline of 3 is correct; it does mention 'category' as a returned field, which is a mild but benign ambiguity against the filter param.

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 (list engines) and spells out exactly what each entry contains (id, the question it answers, category). The 'call this first' framing positions it clearly as the discovery entry point distinct from describe_engine/run_engine, so an agent can place it in the workflow without opening the schema.

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?

Explicitly says when to call it ('when you need to compute something ... rather than estimate it') and backs that with concrete trigger examples spanning unit economics, forecasting, SEO scoring, and pricing. It implies 'don't estimate' as the exclusion, but does not name the follow-up siblings (run_engine, describe_engine) as alternatives, so it stops just short of the top score.

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