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

Goes well beyond the annotations: it discloses that further-reading links are search URLs and nothing is fetched from them, and that when not connected the observed layer is unrecorded rather than empty. These are non-obvious behaviors an agent would otherwise get wrong, though it does not mention rate limits or result ordering.

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?

Front-loads what the tool returns and packs source-layer detail efficiently. The sentences are long but each carries distinct information; the connectivity caveat earns its place despite adding length.

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?

With an output schema present, the description needn't enumerate return fields, yet it still explains what each evidence piece contains and flags the wiki staleness caveat and the unrecorded-vs-empty distinction. Complete enough for an agent to call it correctly.

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 both parameters are already documented, and the description adds nothing specific about the limit or question format beyond the schema. The detail about observed facts requiring three installs informs content, not the parameters themselves, so 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: it returns the evidence behind a question, each piece carrying claim, source URL, licence and date. Covers what layers of evidence exist (observed, curated, 2023 wiki). It does not explicitly distinguish itself from siblings like search_knowledge, so it stops short of a 5.

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 phrase 'for an answer that cites its sources' implies when to reach for this tool over a plain search, and 'Returns evidence rather than prose' reinforces that. But no sibling is named as an alternative and there are no explicit when-not conditions, so usage is only implied.

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