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

Annotations already signal destructive and non-read-only behavior; the description goes further by warning that enabled=true starts spending PostHog Vision credits and by explaining the write-tier approval flow. It does not mention update semantics like partial vs full replacement or response behavior, but the key risks are disclosed.

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 description is three tightly written sentences with the most important behavioral warning front-loaded. The bracketed approval note is long but provides actionable governance context rather than fluff.

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?

The description covers purpose, precondition, cost implications, and approval handling, which is solid for a mutation tool. However, with 11 parameters and no output schema, the unclear optional parameters and missing return-value information leave material gaps for an agent trying to make a correct call.

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 only 27%, and the description compensates only partially. It names prompt, enabled, sampling, and credit limit, but leaves scanner_config, scanner_type, emits_signals, description, name, and sampling_rate unexplained, all of which an agent would need to use the tool effectively.

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?

The description states a specific action ('Update a Replay Vision scanner') and names the editable dimensions (prompt, enabled, sampling, credit limit), clearly distinguishing this from sibling create/delete/get/list tools. The added note that enabled=true starts spending credits reinforces what the tool actually does.

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?

It explicitly says 'Use when changing a scanner or turning spend on' and gives a precondition ('Only works if PostHog is connected'). It does not explicitly name alternatives or when not to use the tool, so it stops just short of full routing guidance.

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