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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=true and idempotentHint=false, so safety is covered. The description adds genuinely valuable non-schema behavior: the ~10.1 credit cost per call, the fixed-price nature of the light tier, that the result reports credits charged, and the legacy-path trap. However, it discloses nothing about how charges are incurred on failure or partial results, which matters for a metered, non-idempotent 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?

Front-loaded with the outcome, then routing, then cost and the legacy-path constraint – all in roughly 90 words with no filler. The cost/dependency rule is compressed into one dense sentence that an agent may need to reread, but nothing is wasted.

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?

An output schema exists, so return-value explanation is rightly omitted, and the description still flags the credits-charged field. For a 19-parameter tool it covers the highest-stakes parameters (effort, maxCredits, filter fields) but says nothing about topic, recencyDays, maxResults, providers, outputSchema's effort dependency, or the mode/strategy fields.

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 only 47% schema coverage across 19 parameters, the description earns credit for explaining that effort controls depth and cost (light default, fixed price), that maxCredits is a hard ceiling, and that 'search filters' such as includeDomains also bypass the legacy path. It leaves the mode enum (fast/balanced/comprehensive) and the legacy strategy field unexplained, which is a real gap given they overlap conceptually with effort.

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?

The first sentence names a specific verb and deliverable ('Get a grounded, current answer with inline source references') and explains the mechanism (searches, reads sources, synthesizes). It explicitly separates itself from router/web-search ('sources only') and router/web-extract ('read known URLs'), so an agent can route without opening a 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 when-to-use condition ('when you need an answer, not a list of links') and names two alternative tools with their selection criteria. It also adds a critical operational warning: without effort plus maxCredits or search filters, the call silently falls back to a sources-only result with no answer.

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