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

With no annotations, the description carries the burden of disclosing behavior. It mentions that history accumulates as plans are re-verified, which gives insight into data freshness, and states ordering (newest first). However, it does not explicitly confirm it is a read-only operation or describe any side effects, leaving some ambiguity.

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 is succinct, comprising two sentences that front-load the core purpose and ordering, followed by a useful note on how history accumulates. No extraneous words or unnecessary details.

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 tool with no output schema, the description covers the essential aspects: it returns dated snapshots, is time-series specific, and clarifies data accumulation. It does not detail the return format or potential limits, but given the simple nature and no annotations, it is reasonably complete.

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 description does not explain the meaning or relationship of the 'plan' and 'brand' parameters, and the schema provides no descriptions (0% coverage). The phrase 'for one plan' implies 'plan' is central, but the role of 'brand' is entirely unexplained, offering no added value beyond the bare parameter names.

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 states the tool's function: retrieving price snapshots over time for a specific plan, with explicit ordering (newest first). This distinguishes it from siblings like compare_providers or list_providers, which focus on provider comparisons or listings.

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 clearly implies when to use this tool (when historical price snapshots for a single plan are needed) and emphasizes 'one plan', setting it apart from multi-plan tools. However, it does not explicitly mention alternatives or state when not to use it, so it lacks explicit exclusions.

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