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

Annotations already declare the tool read-only and idempotent. The description adds a useful behavioral cue that the data is 'factual listing data, not a recommendation,' and clarifies that the price returned is the lowest published monthly price. It does not disclose data freshness, what 'published' means, or how the listing is constructed.

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 short sentences: the first states the purpose and key behavior, and the second adds an important interpretive caveat. Every sentence earns its place, and there is no filler or repetition.

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 tool has no output schema, five parameters, and three undocumented parameter semantics. The description partially explains the return behavior (providers with lowest published monthly price) and uses annotations to cover safety, but it leaves filter meanings and the exact response shape to inference. This is adequate but not 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?

Schema description coverage is only 40%; medication and limit have descriptions, but cqc_registered, published_price_only, and max_monthly_price_gbp do not. The tool description provides no additional meaning for any parameter and does not compensate for the undocumented fields, even though their names are somewhat self-explanatory.

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 uses a specific verb ('Find') and identifies a clear resource: UK providers of a weight-loss medicine, with the output criterion of the lowest published monthly price. It is clearly distinct from siblings like get_provider and list_medicines by resource and scope, though it does not explicitly name them.

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 usage context is implied: use this when you need provider listings with price data for a weight-loss medicine, not when you need a recommendation. However, there is no explicit discussion of when to prefer get_provider, list_medicines, or match, and no stated exclusions.

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