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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior, so the safety profile is fully covered. The description adds one genuinely new behavioral fact — that returned links carry a cp0x referral code — which matters since there is no output schema. It says nothing about result size, ordering, or what happens with limit=null, leaving the disclosure modest.

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, front-loaded with the resource and scope, and the usage cue follows immediately. "With optional venue filtering" slightly duplicates the schema but is justified as a scannable headline of capability.

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?

A simple zero-required-parameter read tool with rich annotations and no output schema needs little more than purpose, usage cue, and a hint about returned data — all of which are present. Only an indication of result cardinality or ordering would materially improve it.

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%, with both limit and query fully documented in-schema, so the baseline is 3. The description's "optional venue filtering" only loosely gestures at the query parameter and adds no syntax, matching, or ordering detail beyond 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 ("List cp0x referral deals") plus the scope qualifier (optional venue filtering), which cleanly separates it from the singular get_deal sibling. It does not name an alternative tool explicitly, but the plural-list vs. single-get distinction is self-evident.

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?

"Use this when looking for deals by venue or browsing the deal catalog" gives a clear selection context and maps to the query parameter. No exclusions or pointers to alternative tools (e.g., get_deal for a known slug) are stated, so it falls 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.