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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail beyond annotations: it emphasizes that packages are 'real, currently bookable' and that an invalid shoot_type_id is rejected for that photographer. This gives an agent a sense of validation behavior and real-world availability.

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 sentences, front-loaded with the core action and resource, then the key behavioral note and a practical next step. No filler or repeated schema content. Every sentence earns its place.

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 two-parameter read-only tool with no output schema, the description conveys what is returned (packages with prices in Toman), how invalid input behaves, and how to use the result. It could mention where to obtain a valid shoot_type_id or describe the package output shape more fully, but it is adequate for an agent to invoke correctly.

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 coverage is only 50%, so the description must compensate. It clarifies that shoot_type_id filters packages and that photographer_uid identifies the photographer, but it does not say where shoot_type_id comes from or add much detail beyond the schema. It does mention the returned package id, which is useful for follow-up, but the parameter-level guidance remains incomplete.

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 ('List') and clearly names the resource: currently bookable packages with prices in Toman for a specific photographer and shoot_type_id. It also distinguishes the tool from siblings like create_reservation by framing it as a read-only lookup that returns package ids for later use.

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 indicates when to use this tool: when you need a photographer's bookable packages for a shoot type. It also gives a concrete next step ('Use the returned package id with create_reservation'), which helps an agent chain the call correctly. It does not explicitly state alternatives or exclusion cases, but the sibling set and read-only framing make the intended usage clear.

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