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

Adds substantial behavior beyond the annotations: the AI lead capture picks up changes in the background within about a minute, a no-op request returns the field unchanged (reinforcing idempotentHint), and removed enum choices do not erase existing lead values ('Leads keep values you remove'). This is precisely the destructive/async/error detail an agent needs and that annotations alone don't convey.

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-loads the core purpose, then layers constraints and edge cases in a tight, information-dense block with no filler. Slightly dense but every sentence carries a distinct constraint, so nothing reads as wasted.

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?

No output schema exists, and the description covers the no-op return case plus the 422/404 error paths and async propagation, which is nearly everything an agent needs. It does not describe the general success return shape, a minor gap for a mutation with no output schema.

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 100%, so the schema already documents every parameter in depth (label, options ordering/uniqueness, agent_id error codes, field_key matching). The description largely summarizes which of those fields are mutable rather than adding new syntax or format meaning, so baseline 3 is 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 and resource ('Change a lead field') and pinpoints exactly which aspects are mutable (label, required, choices) versus fixed (key, type). It differentiates itself from create_lead_field by noting that a key/type change requires adding a new field, so an agent can route correctly without opening a 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?

Gives clear when-to-use context and a concrete exclusion: built-in fields and lead statuses cannot be changed through the API (422 system_field), and key/type changes require the sibling create path. It stops short of naming the dashboard/alternative tool for built-in edits explicitly, leaving that to inference.

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