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

Annotations already declare non-read-only, idempotent, non-destructive; the description adds real context beyond them by naming the required write_crm scope (an auth prerequisite the annotations do not convey). It stops short of describing side effects, such as whether moving to 'won' or 'lost' triggers downstream automation.

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?

Two compact sentences, zero filler, with the core action and valid values front-loaded ahead of the precondition.

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?

For a two-required-param mutation with no output schema, the definition covers the action, the allowed values, and the auth requirement. The remaining gap is behavioral outcome (what happens on a won/lost transition and what the call returns), which is a minor omission rather than a blocking one.

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%, so the baseline would be 3, but the description adds genuine meaning the schema lacks: the schema's stage field only says "Target stage." with no enum constraint, and the description supplies the six allowed values. It says nothing extra about deal_id or idempotency_key, though those are already well documented in the 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?

States a specific verb and resource ("Set a deal's stage") and enumerates the six valid stages, so an agent knows exactly what the tool mutates. It does not name a sibling alternative (e.g. create_deal for new deals), but the purpose is unambiguous.

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?

Usage is implied by the verb+resource pairing and the stage list, and the required write_crm scope signals a precondition. There is no explicit when-to-use/when-not guidance or mention of alternatives such as create_deal or a campaign tool.

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