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

Goes well beyond the annotations: per-keyword cost (~$0.015), the >8-keyword background threshold, the returned status=started with run_id and estimated_seconds, and the async polling contract via list_tracked_keywords.last_check.status. It does not explain why the tool is marked destructiveHint=true/non-read-only (account spend, mutating last_check state), which is the one behavioral trait an agent might not anticipate.

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?

Two tight sentences, front-loaded with purpose and cost, then the prerequisite, the async behavior, and the do-not-recall warning in order of operational need. Every clause carries information an agent must act on.

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?

No output schema exists, yet the description fully compensates by describing the immediate return (status=started, run_id, estimated_seconds) and the terminal states (running → completed | partial | failed with the error) read elsewhere. Nothing needed to call it correctly or interpret its result 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?

Schema description coverage is 100% and the single parameter (site_id) is fully documented in the schema, so the baseline is 3. The description implies scope ('all tracked keywords') but adds no syntax or format detail beyond what the schema already provides.

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 ('Live rank check for all tracked keywords against the brand's ranking location') and scopes it to the brand's ranking location. An agent can separate it from siblings like tracked_keyword_performance, keyword_competitor_ranks, or set_ranking_location without opening any 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 prerequisite ('set_ranking_location first'), an explicit exclusion ('Do not call again while it is running'), and routes the agent to the right alternative for results (list_tracked_keywords). Nothing about when to invoke or avoid it 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.