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

With no annotations, the description carries the full burden and does so well: it discloses idempotent behavior (returns the active run if one exists), the incremental cost model (carried-forward pages cost no credits; full mode bills every page), the required WRITE-scoped token, the EDITOR/ADMIN/OWNER role, and credit consumption. These are exactly the side-effect and auth facts an agent needs before invoking a write tool.

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 compact sentences, front-loaded with the purpose, then behavior, then auth/cost. Dense but nearly every clause earns its place; the mode sentence slightly overlaps the schema description.

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?

Although there is no output schema, the description identifies what is returned (the queued CrawlRun, or the already-active one). Combined with auth, role, cost, and incrementality details, an agent has everything needed to invoke this 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% and the mode enum's description already explains incremental vs full and their billing implications, so the schema does the heavy lifting. The description's mode guidance reinforces but does not add meaning beyond the schema, making the baseline 3 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 (Enqueue) plus resource (recursive crawl run for a site) with clear scope, and the idempotent-return sentence clarifies it creates-or-returns a crawl run. This is readily distinguishable from read siblings (get_crawl, list_crawls) and from cancel_crawl.

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 clear when-to-use context: re-crawls are incremental by default, and 'Pass mode="full" to re-fetch every page' tells the agent when to override. It also explains the case where an active run is returned instead of a new one. It stops short of naming alternatives like recrawl_pages, so it isn't a full 5.

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