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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so the safety profile needs no restating. The description adds genuine context beyond them by disclosing what a group deal result covers (goal buyers, deal length, inclusions, region, payment and tax terms), which matters since no output schema exists. It says nothing about behavior for a missing or invalid id, which keeps it from a 5.

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 short sentences with zero filler, and the core purpose plus lookup key are front-loaded ahead of the supplementary field list. Every clause carries information.

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 one-parameter read lookup with no output schema, the description gives enough to call it correctly and sketches the return contents for group deals. The only meaningful omission is what happens on an unknown id, which is minor at this complexity.

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%; the single id parameter is already documented in the schema as "Deal id from search_deals." The description repeats that meaning rather than adding format or constraint detail, so baseline 3 applies.

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 names a specific verb and resource ("Full details of one deal") plus the lookup key ("by its id"), and it points at search_deals as the origin of that id. It stops short of explicitly contrasting itself with request_group_deal, so the sibling differentiation is only partial.

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 parenthetical "(from search_deals)" implies the workflow — search first, then fetch by id — but usage is only implied. There is no statement of when not to use it or when request_group_deal is the correct alternative instead.

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