Prescription Cost Analysis

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

No annotations are provided, so the description carries the full burden of disclosing behavioral traits. It mentions the scope of data but does not explicitly state that the operation is read-only, lacks any side effects, or requires specific permissions. It also does not describe response structure, pagination, or error behaviors. Given the lack of annotations, this is a significant gap.

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 two sentences long, front-loaded with the primary action, and includes only essential information. The first sentence states the purpose, and the second adds scope and an explicit alternative. There is no redundant or extraneous content.

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?

There is no output schema, so the description should offer some idea of what the tool returns. It does by saying 'Shows aggregate costs and volumes.' For a tool with five parameters and a relatively simple query purpose, the description is adequately complete, though it omits details like pagination or resource auto-discovery (which are in the schema).

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 description coverage is 100%, so the baseline is 3. The description does not add details about any specific parameter beyond what is already in the schema, such as the meaning of limit or bnf_code. It only adds context about the national-level aggregation, which is not parameter-specific. The schema already provides clear descriptions for all five parameters.

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: 'Get prescription cost statistics from the national Prescription Cost Analysis (PCA) dataset.' It explicitly notes the national-level scope and differentiates from the sibling tool by directing users to prescriptions_search for practice-level data, satisfying the requirement for a specific verb, resource, and sibling distinction.

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 explicit usage context: it is for national aggregate costs and volumes, and it explicitly says 'not by practice.' It also names the alternative tool for practice-level data ('Use prescriptions_search for practice-level data instead'), giving clear when-to-use and when-not-to-use guidance.

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