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

With no annotations supplied, the description carries the full burden, and it does add genuine non-obvious behavior: the tool refuses with a named 'do_not_answer' signal when content is drifted or unverified and 'never guesses'. It does not describe what happens on an unknown or malformed fact_id, nor any auth or rate-limit context.

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?

Two short sentences with zero filler; the core action is front-loaded and the refusal guarantee follows immediately as supporting context. Every clause carries 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?

For a one-parameter read tool with no output schema, the description covers what it returns (a verified fact or a refusal) well. It is incomplete on the one thing an agent must know before calling: how to produce a valid fact_id.

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 0% for the single required parameter, so the description would need to explain fact_id. It never states the identifier's format, where valid IDs come from, or whether they are discoverable via the list sibling, leaving the only parameter effectively undocumented.

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') scoped to a named domain ('the selfemployuk pack'), and the singular 'one' implicitly separates it from a bulk-listing sibling. It stops short of naming any sibling explicitly, so the differentiation relies on inference from 'one' versus a list operation.

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?

Usage is implied by 'Get one verified fact' and by the refusal clause, which tells the agent this call may legitimately return no answer. There is no explicit guidance on when to prefer this over a listing or changes sibling, nor any precondition for obtaining a valid fact_id.

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