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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds meaningful behavioral detail beyond that: it characterizes the returned payload per aspect (billing rules/cost drivers, expected bills, full ontology) and flags which is best for grounding answers, which matters 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?

Dense but front-loaded: the core purpose comes first, followed by the aspect breakdown. Every clause earns its place, though the semicolon-separated aspect list reads as a run-on and could be slightly easier to scan.

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 only two parameters, full schema coverage, and annotations covering the safety profile, the main remaining burden is explaining return content, which the aspect descriptions handle well. The one notable gap is how the caller obtains a valid canonical slug (likely via resolve_procedure), which is left implicit.

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%, so the baseline is 3, but the description goes further by explaining what each 'aspect' enum value actually returns rather than just repeating the schema's 'Default facts'. It does not add anything about slug format or how to obtain a canonical slug, which the schema only lightly covers.

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 resource and scope: 'Structured knowledge about one procedure,' with a clear verb-like intent of retrieving details for a single slug. It does not, however, distinguish itself from the sibling 'resolve_procedure' or 'list_procedures', leaving the agent to infer which retrieval tool to pick.

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 real guidance on aspect selection ('facts' is 'best for grounding an answer'), which is useful decision support. But it never states when to call this tool at all versus resolve_procedure/list_procedures, or what prerequisite (a resolved canonical slug) it needs, so usage context is only implied.

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