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

Annotations already indicate non-read-only, idempotent, non-destructive, but the description adds substantial behavioral context: concurrency protection via expectedUpdatedAt, stale_revision return with currentUpdatedAt, refusals of unknown/owner/lifecycle keys, pipeline stage rules, idempotency semantics, and the security warning that CRM field values are untrusted data. No contradiction with annotations exists.

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?

Every sentence earns its place: core purpose, concurrency mechanism, refusal rules, pipeline routing, alternatives, idempotency, and security note. The most important usage constraint (expectedUpdatedAt) is front-loaded immediately after the purpose, and the description remains tight despite covering complex behavior.

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?

Given six parameters, no output schema, nested data objects, and complex mutation semantics, the description covers all critical aspects: concurrency, return behavior, parameter restrictions, pipeline rules, idempotency, and security. An agent has enough information to call the tool correctly and avoid common pitfalls.

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?

With schema description coverage at only 17%, the description carries the burden of explaining parameters. It explains expectedUpdatedAt (must match current updatedAt from get_record), idempotencyKey (applies once), data (fields to update, unknown keys refused), and pipelineStageId/pipelineId combinations. This meaningfully exceeds the bare 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?

The description opens with 'Updates the given fields of one record,' a specific verb+resource statement. It further distinguishes this tool from update_activity, update_pipeline, and similar siblings by detailing record-specific behaviors such as pipelineStageId handling and links to close_record/get_record_action_context.

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?

The description gives explicit guidance on when to use this tool: updating fields of a record, moving deals/leads between stages or pipelines, and using idempotencyKey for retries. It also states when not to use it, such as for won/lost stages, and names the alternatives (get_record_action_context and close_record) directly.

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