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

Annotations supply only destructiveHint=true, so the description carries most of the burden. It does add real value by disclosing the payload transformation (amountMicros + currencyCode collapse into a nested amount object) and the underlying POST /rest/opportunities endpoint, but it says nothing about idempotency, error behavior, auth requirements, or what happens to unknown fields routing through `extra`.

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?

Three short clauses, correctly front-loaded with the purpose before the field mechanics. Minor redundancy with the schema on the amount composition, but nothing wasted at the sentence level.

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 an 8-parameter create tool with a fully documented schema, the description covers the essentials. The remaining gap is that with no output schema defined, it never indicates what the call returns (e.g. the created opportunity's id), which a caller needs to chain into follow-up calls.

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 baseline is 3. The description's parameter notes (`name` required, amount composition) largely restate what the schema property descriptions already say, so it adds little beyond the structured fields.

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 verb and resource ("Create a new opportunity (deal)") and the alias "deal" helps map to domain language. It clearly separates this from the get/update/list opportunity siblings via the verb, but never names or contrasts an alternative explicitly.

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 only implied by the verb: you call it when you want a new opportunity record. There is no statement of prerequisites, when to prefer update_opportunity instead, or any exclusion — a caller must infer everything from the tool name.

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