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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds context beyond that: "Changes nothing" reinforces the read-only nature, and "Premium plan; runs daily by itself for clients with Autopilot in shadow or on" discloses a plan gate and autonomous scheduling behavior not in the annotations.

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?

The core purpose is front-loaded in the first clause, and the dense parenthetical enumerations are informative rather than filler. The opening sentence is long and packed, but every clause earns its place by specifying what gets tested.

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 no output schema, the description carries the return-value burden and does so: it explains what signals are tested, that a broken form is distinguished from a broken tracking tag, and that the outcome is a named likely cause and fix. Nothing needed to call it 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?

Only one parameter (client) with 100% schema coverage, and the schema already documents it as "Client name from list_clients". The description adds no additional meaning about the parameter, so baseline 3 applies.

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 (check/diagnose) and resource (leads) with an enumerated scope: form-lead and phone-tap events, thank-you pages, Google Ads conversion actions. It clearly distinguishes itself from siblings like form_test (form-only) and tracking_spec by describing a multi-signal diagnostic that also names the likely cause.

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 explicit trigger phrases: "why did leads stop", "is the form working", "no leads this week", which tells the agent the situations that select this tool. It does not name alternative siblings or state when NOT to use it, so it stops short of a full routing guide.

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