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

Annotations already declare idempotentHint=true, destructiveHint=false, and readOnlyHint=false, so the '(idempotent)' note in the description is redundant. The genuinely additive piece is the outcome disclosure ('stage converted, status won'), which tells the agent what state mutation occurs. Missing are failure behavior for an unknown or malformed ref code (the schema requires a 6-hex pattern) and any note about which permissions or side effects conversion triggers.

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?

A single front-loaded sentence that leads with the action and appends the resulting state. It is slightly padded by restating the idempotency flag the annotations already carry, but nothing is materially wasteful.

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 three-parameter mutation with annotations covering safety and idempotency and no output schema, the description covers purpose and end state. It still leaves unclear what 'converted' entails beyond stage/status, what happens on an invalid ref, and how it relates to the very similar siblings, which is enough to call it but not fully self-sufficient.

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 67%, and the schema itself explains refCode (6-hex attribution key) and at (ISO 8601 timestamp); the description only echoes 'by ref code'. The undocumented parameter, signupRef, is not clarified in the description, so it does not compensate 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?

The description states a specific verb and resource ('Convert a deal') plus the lookup key ('by ref code'), and it names the resulting state ('stage converted, status won'). It is clear in isolation, but it does not distinguish itself from near-identical siblings such as mark_deal_won and move_deal_stage, which produce overlapping outcomes.

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?

There is no guidance on when to use this instead of mark_deal_won, move_deal_stage, update_deal, or find_deal_by_ref plus a separate update. The only implied context is that the deal is identified by an attribution ref code, and even that has to be inferred from the phrase.

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