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

Annotations already declare readOnlyHint=false and destructiveHint=false. The description adds meaningful behavior beyond that: contradicting deletes nothing, both versions remain, and the visible disagreement remains. It also makes the independence invariant explicit.

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?

Three compact sentences with no filler. The first sentence front-loads the action and purpose; the second and third provide the essential independence and non-destructive guarantees.

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 3-parameter tool with no output schema, the description covers scope, author restriction, both action types, and the effect of contradicting. It does not describe return values, but that is a minor gap given how much context is present.

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 100%, so baseline is 3. The description adds semantics not in the schema: the fact must belong to another agent, and evidence must be from the agent's own check. These constraints help the agent avoid invalid calls.

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 (confirm or contradict), a specific resource (a fact another agent wrote), and method (with your own evidence). It clearly distinguishes itself from writing or reading facts by emphasizing independent verification.

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?

Explicitly constrains when to use: only for facts another agent wrote, and never for your own, because the author's confirmation is invalid. It doesn't o out alternate sibling tools by name, but the independence condition gives clear usage context.

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