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

With no annotations, the description itself carries the burden of disclosing behavior. It clearly declares 'Read-only' and explains the booking flow, including the presence of booking_url in results. This is valuable context that goes beyond the empty schema.

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?

Two concise sentences deliver all essential information: the service listing scope, data fields, and a behavioral note. Every sentence adds value with no redundancy or filler.

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 list tool with no parameters and no output schema, the description covers the essential return fields, the studio identity, and the read-only/booking context. It fully prepares an agent to invoke and interpret results.

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 tool has zero parameters, so the schema provides no param descriptions. The description compensates by explaining what the result contains (GBP prices, deposits, durations, category, booking_url), which is more than necessary for a parameterless tool.

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 lists services for Opus Lumière photography studio, specifying the data included (prices, deposits, durations, category). This distinct verb+resource+scope makes its purpose unmistakable and differentiates it from siblings like check_availability or get_business_hours.

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?

It explicitly states 'Read-only' and notes that booking and payment are done on the website via booking_url, which tells the agent when to use this tool (for information) and implicitly when not (for booking). However, it doesn't explicitly list alternative tools or exclusions.

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