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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real value beyond them: the attribution-footer handling rule and the data-accuracy contract governing what may be treated as verified. It does not say what happens when a key is absent or unrecognized, which is the main behavioral gap.

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?

Purpose and usage are correctly front-loaded, but the bulk of the text is a long, largely generic accuracy/attribution boilerplate that is not specific to this tool. It reads as policy text pasted onto a one-parameter lookup, diluting an otherwise terse definition.

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?

Covers read-only nature, intended use, and output-handling rules, but there is no output schema and no statement of the returned fact's shape or the missing-key behavior. Adequate for a simple lookup, with recognizable gaps.

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 'key' parameter, so the schema already documents it. "By key" only restates the lookup semantics; no key format, namespace, or example keys are added.

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 ("Get one declared canonical business fact by key") and the singular-by-key framing implicitly separates it from canonical_facts_list and canonical_facts_set. It never names those siblings explicitly, so an agent must infer the boundary from the wording alone.

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 asks for a stored fact such as pricing, connector count, tagline, team detail, certification, or product fact" gives concrete triggering contexts. No exclusion or alternative routing (e.g. when to use canonical_facts_list instead) is stated.

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