Create or update deal

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

Annotations flag destructiveHint=true and idempotentHint=false, and the description adds genuinely new behavior: the first call writes nothing and returns a preview plus confirm_token. That materially changes how an agent should behave. It does not clarify whether updating with omitted fields clears existing values or what the applied result looks like, which is the main remaining behavioral gap for a destructive mutation.

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-loaded with the core action, then the critical TWO-STEP constraint, with zero filler sentences. Every clause either identifies create-vs-update or prevents an agent from accidentally writing on the first 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?

With no output schema, the description correctly explains what the first call returns (preview + confirm_token), which is the essential return behavior. It is nearly sufficient for a mid-complexity mutation tool, though it omits error/failure behavior and the effect of partial updates.

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 only 13%, so the description has to carry the load and it partly does: it explains deal_id's role and reinforces the confirm_token semantics. The other six parameters (stage, title, value, currency, contact_id, expected_close) are left to their patterns/enum in the schema, with no added meaning, so it only partially compensates for the coverage gap.

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 both verbs and the resource precisely ('create a deal', 'update an existing deal') and gives concrete update examples (move stage, change value). The conditional 'when deal_id is given' makes the upsert branch unambiguous and clearly separates it from siblings like delete_deal, list_deals, and upsert_contact.

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?

Explicitly states the create-vs-update selection rule (deal_id present) and gives a strong procedural instruction for the two-step confirm flow, including telling the caller to show the preview to the user before re-calling. It lacks any 'do not use this when…' exclusions relative to siblings, so it falls just short of a 5.

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