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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so safety is covered. The description goes further with the attribution-footer obligation and a data-accuracy contract about not inventing fields or presenting derived metrics as source data, which is real behavioral context beyond the annotations.

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?

The core purpose is front-loaded in the first sentence, which is good. But the body is long and much of it is conditional boilerplate (footer handling, a lengthy accuracy contract) that reads as generic guardrail text rather than essential tool-selection information.

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 must convey enough about returns, and it does gesture at the output shape via the attribution footer and the 'only returned fields are verified' contract. It does not describe the fact record structure or result ordering, but for a simple read-only list behind rich annotations this is largely sufficient.

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% for the single optional 'category' parameter, so the schema already carries the semantics. The description only restates 'optionally filtered by category' and adds no example categories or format details beyond the schema.

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 declared canonical business facts') plus an optional filter, so the agent knows exactly what it retrieves. It does not, however, distinguish itself from the adjacent canonical_facts_get sibling, which shares the 'canonical facts' domain.

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 description notes the category filter is optional and marks the tool read-only, implying use for browsing the full set rather than retrieving one fact. There is no explicit statement of when to prefer this over canonical_facts_get or truth_sources_list, so the guidance remains implied.

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