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

Goes well beyond the annotations by disclosing the pricing model (EUR 0.0003 first page, 0.0002 per extra page), latency (~30s/keyword, ~a minute for 10 pages), that the tool blocks waiting for results, the pending_ids handoff path, and the output boundary (titles/snippets/URLs, not page content). This is exactly the operational context an agent needs before invoking a slow, metered 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?

Dense but front-loaded: what it does first, then how to use it, then cost and duration, then the output boundary. The mid-sentence enumeration of block types is long, though it earns its place by naming the returned structures; nothing is padded or repeated.

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 11 parameters, no output schema and a metered async call, the description covers the missing pieces: cost, duration, blocking-vs-pending behavior, and what the response actually contains. An agent has everything needed to call it correctly and to decide whether to wait or poll.

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, but the description adds real meaning on top: cost/time scaling with depth, the domain parameter reframed as 'where does this site rank', priority as a queue-jumping lever, and the async contract of wait_seconds. It stops short of adding anything for blocks/geolocation beyond what the schema already documents.

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 concrete verb and resource: collects the real Google SERP for keywords in a real browser, enumerates the block types returned and the per-item ranking fields (rank_type, rank_serp, page, pixel position). This is specific enough that an agent can distinguish it from get_serp_results (pending fetch) and google_maps 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?

Explicitly says when to reach for it ('to know what Google actually shows for a query, in a given country, language, city and device') and routes batched work to get_serp_results and wait_seconds=0. It does not contrast itself against siblings like google_maps or ai_overview_sources, so it is clear context but without full alternative routing.

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