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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the tool refuses with 'do_not_answer' when data is drifted or unverified and never guesses, which is meaningful beyond the schema, but it omits permissions, response format, and what 'drifted' concretely means.

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 description is two short sentences, front-loaded with the core purpose and followed by the critical refusal behavior. There is no redundant or filler wording.

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?

For a simple one-parameter read tool with no annotations or output schema, the description covers the basic purpose and refusal behavior. It still leaves important gaps around obtaining a valid fact_id and understanding the response shape and refusal payload.

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 0%, and the only parameter is an undocumented fact_id string. The description implies that fact_id selects one fact but does not explain its format, where to obtain it (e.g., via maternityuk_list_facts), or any constraints.

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?

The description states a specific verb and resource: 'Get one verified fact from the maternityuk pack.' The phrase 'one verified fact' implicitly separates it from list-style siblings like maternityuk_list_facts, but it does not explicitly name those siblings or clarify scope beyond the 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 intended usage is implied: retrieve a single known fact by fact_id. However, it gives no explicit when-to-use guidance, no alternative such as maternityuk_list_facts for discovering fact IDs, and no prerequisites or exclusions.

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