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

Annotations already cover the read-only/idempotent safety profile, and the description adds context those annotations cannot express: the returned answers are personal data stored encrypted, only two endpoints expose them, and access is gated on administrator role plus the facebook_marketing feature. Those are exactly the operational and privacy constraints an agent needs before calling.

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 short sentences, front-loaded with the core behavior, then progressively narrower detail on data sensitivity and access gating. No filler and the constraints are visually emphasized, so skimming yields the right call.

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, so the description carries the return-value burden and does so ('Returns one lead including the answers submitted on the form'). Combined with the access and feature prerequisites, 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% (both `id` and the `fields` enum array are documented inline), so the schema does the heavy lifting. The description adds no detail about the `fields` selector or how answers interact with the field projection, leaving this at the baseline for fully covered schemas.

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 ('Get a lead') plus scope ('Returns one lead including the answers submitted on the form'), which separates it from the list_facebook_leads sibling. The second sentence clarifies exactly what payload comes back, so an agent can distinguish single-record retrieval from the list endpoint 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?

It names the alternative path for answers ('only this endpoint and the list with `include=answers` return them') and gives prerequisites: administrators only and the `facebook_marketing` feature. It does not explicitly say when to prefer this over list_facebook_leads for lookup/search, so it stops short of full when/when-not guidance.

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