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

Explains the otherwise puzzling readOnlyHint=false: the call 'creates or refreshes an idempotent public report URL for the receipt, retained for up to 90 days,' which matches idempotentHint=true and destructiveHint=false. It also discloses determinism ('same inputs always produce the same output, with no LLM in the path') and a legal caveat, adding substantial context the annotations cannot convey.

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?

Front-loads purpose and outputs before side effects and the disclaimer, and each sentence carries information. The closing legal caveat is slightly verbose across two sentences but is genuinely relevant to correct reliance on the result.

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 carries the full burden of describing return values and does so thoroughly (regulations and Controls triggered, numeric complexity score, blocker count, cohort breakdown), plus the report-URL side effect and determinism guarantee. Nothing an agent needs to call it correctly is missing.

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%, so the schema already documents every parameter, including the closed-catalog constraint and the audience enum. The description restates the input categories (features, markets, age bands, optional business model) but adds no syntax or format detail beyond the schema, so 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 ('Run Magist's deterministic compliance engine over a product description') and enumerates the outputs: regulations/Controls, complexity tier, blocker count, cohort breakdown. An agent can distinguish it from lookup/search siblings because this tool computes derived requirements rather than retrieving existing records.

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?

Gives situational context (research purposes, not a legal determination, consult counsel) and points to list_feature_catalog for valid ids via the schema. However it never states when to prefer this over alternatives like lookup_regulation or search_regulations, so routing guidance is only implied.

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