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

Annotations already declare destructiveHint=true, but the description goes well beyond them: it explains which facts are protected, the exact error code (FD-006) and that the failure reports a reference count, and the nuance that rules in deleted groups are excluded from that count. This is exactly the failure-mode detail an agent needs before invoking a destructive call.

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?

Four short sentences, front-loaded with the action and followed by the blocking conditions. Every sentence carries a distinct constraint; nothing is redundant or padded.

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 single-parameter destructive tool with no output schema, the description covers preconditions and error behavior well. It does not address permissions/authorization requirements or whether the deletion is permanent or recoverable, which are the remaining gaps for a destructive operation.

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?

Only one parameter (factId) and schema description coverage is 100%, so the schema already documents it as the fact definition UUID. The description adds no syntax, format, or lookup guidance beyond that, which is the expected baseline when the schema does the work.

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 ('Delete a fact definition'), which cleanly separates it from the sibling mutators lexq_facts_create and lexq_facts_update. The added precondition clauses make the scope of the operation unambiguous.

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 explicit when-not conditions: system facts cannot be deleted, and facts referenced by rules fail with FD-006. It also states the remediation path ('Remove the references first'). It stops short of naming an alternative tool for the cases it rejects, so it falls just below the top band.

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