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

Annotations already mark readOnlyHint true and openWorldHint false. The description adds the key behavioral split between empty and populated parameters, explaining exactly what each call returns. No contradictions or hidden side effects are implied.

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?

The description packs a lot into one efficient sentence without fluff. It front-loads the domain and content groups, then explains conditional behavior. Slightly dense but every phrase earns its place.

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 simple read-only lookup with one optional parameter and no output schema, the description fully covers both invocation modes and the shape of each response. An agent can call it correctly without further information.

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?

The schema covers the 'signal' parameter 100% with 'A signal slug from the list', and the description reinforces that meaning while adding the crucial optionality behavior: omitting returns the full list, supplying a slug returns signal-specific details. This goes beyond schema-only information.

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 scope: 'The 40 moments in a dealership sale worth acting on', enumerated in six named groups. It clearly distinguishes this as a lookup/reference tool for conversation signals, not a generic glossary or action tool, and the conditional return behavior is explicit.

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 description provides clear context on how to use the tool: without a signal slug it returns the list, with a slug it returns detailed guidance. It does not explicitly name sibling alternatives or exclusions, but the categorical groups effectively define when this tool is relevant.

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