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

Goes well beyond the annotations: it discloses quota consumption ('spends the monitors the plan priced'), partial-success behaviour ('anything left out because the plan filled up'), and the exact idempotency semantics ('the same plan id returns the first result'), which is more precise than the bare idempotentHint flag.

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 triggering condition, then return shape, then cost, then idempotency, then the exclusion. Every sentence carries distinct information; nothing is redundant with the schema or annotations.

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?

There is no output schema, but the description enumerates what comes back (created sites with ids, page checks, dependencies, omissions, next steps) and covers the mutation's cost and repeatability. Nothing needed to call this correctly 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 coverage is 100%, so both parameters are already documented there and the baseline would be 3. The description adds a real semantic constraint on plan_id — reuse returns the first result — and ties confirm to a user-visible confirmation step, which meaningfully extends the schema.

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 action — creating the sites described by a confirmed plan_site plan — and immediately distinguishes it from the planning sibling by requiring a confirmed plan. An agent can tell this apart from plan_site 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?

Explicitly names the precondition ('user has confirmed a plan_site plan and its cost'), the alternative (show them plan_site's summary first), and the exclusion ('not for a plan the user has not seen'). No routing inference is required.

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