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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds genuinely useful behavior beyond them: it returns the closest entries with status, reason and source, and returns "no match rather than guessing" — a meaningful anti-hallucination guarantee. It stops short of describing ranking/threshold behavior, so it is good but not rich.

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 tight sentences, front-loaded with the usage condition, then the behavior, then the fallback. Every sentence earns its place with no repetition of the title.

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?

Output schema exists, so return values need not be explained in detail, and annotations cover the safety profile. The description still completes the picture with the when-to-use rule, the sibling alternative, and the no-match fallback — nothing an agent needs is missing.

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?

With one parameter at 100% schema coverage, the schema already carries the semantics including an example. The description only reinforces the "one specific claim" scope, adding no syntax or format detail beyond the schema. Baseline 3 applies.

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 ("check ... one specific GTA 6 claim or rumor") and explicitly distinguishes itself from the sibling get_facts, which browses the whole database. An agent can tell it apart from get_facts and search without opening either schema.

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 an explicit trigger ("when someone asks whether one specific claim or rumor is true") and names the alternative with its selecting condition ("use get_facts to browse the whole database instead"). Nothing is left to inference.

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