get_signal

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

With no annotations, the description fully discloses the paid nature ($0.01 via x402), the compute-first/settle-after model (no charge on error), the three possible return types, and the behavior without a key (returns 402 price terms). This goes well beyond minimal requirements.

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 essential operational details (cost, types, index, payment, error safety) into a compact set of sentences. It's slightly dense but each sentence contributes value; minor structural improvements could separate payment setup from return types.

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?

The description covers the tool's purpose, parameters, payment prerequisites, and behavioral guarantees (free on error). It lacks explicit response format, but given the absence of an output schema, it could be more explicit about return values; still, it provides enough context for an agent to decide.

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 already documents the single parameter index with its description, including 'omit for the latest.' The description repeats this and adds 'Pass index=N for a specific item,' but no new semantic meaning beyond the schema. Coverage is 100%, so baseline is 3.

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 clearly identifies the tool's function: retrieving a single Polymarket feed item (mover, whale entry, or predetermined signal). It distinguishes from siblings by supporting an optional index parameter and indicating it returns one item, unlike get_signals (plural). The verb 'get' plus specific resource is clear.

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 explains exactly how to use the tool: pass index for a specific item or omit for the latest, and notes the need for PRIVATE_KEY for live payment. It references get_index for obtaining the index, providing contextual linkage. However, it doesn't explicitly contrast when to use get_signal vs get_signals or other siblings.

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