web_search

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

No annotations are provided, so the description carries the full burden, and it does meaningfully more than the name: it discloses the return contract (grounded answer + source URLs, not pages), a token-saving rationale, and a real edge case ('NOT A LIVE SEARCH' prefix means possibly stale). It omits rate limits, freshness guarantees, and auth needs, which keeps it out of 5 territory.

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 purpose and output contract, then usage triggers, then the staleness caveat. Nothing is redundant, though 'done by helpers' is slightly vague and could be tightened.

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 no annotations and no output schema, the description is the sole source of behavioral context, and it covers purpose, return shape, usage triggers, and a notable result-prefix caveat. It leaves out pagination/limits behavior and freshness details, but is sufficient for correct invocation.

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 67%, with query and focus already documented in the schema and the query guidance ('be specific — versions, dates, error text') largely duplicated in the description. The description says nothing about 'focus' or the 'max_results' bound (1-10, default 5), so it adds little beyond the structured fields; baseline 3 is appropriate.

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+resource ('Live web search') and immediately defines the output shape ('short grounded answer + source URLs instead of raw pages'), which implicitly separates it from the sibling web_fetch that returns raw pages. An agent can pick between web_search and web_fetch 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 concrete when-to-use triggers ('docs, error messages, versions, news') and contrasts with the raw-page alternative. It stops short of explicit exclusions (e.g., when to prefer web_fetch or ask_agent instead), but the context is clear enough to route correctly.

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