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

Description adds rich behavioral context: hours are catalog data, not live; always returns as_of; may abstain for venues without hours; advises confirmation. This goes well beyond readOnlyHint annotation by disclosing staleness and abstention. No contradiction with annotations.

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?

Three sentences, each carrying weight: purpose, staleness, abstention, and confirmation advice. No fluff, front-loaded with purpose. Efficient and well-structured.

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 lookup tool with output schema, the description covers critical behavioral aspects (staleness, abstention) and safety (readOnlyHint). An agent has everything needed to call it correctly, including when to be cautious.

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 all parameters are already documented. The description adds no extra parameter-level detail, only contextual information about the catalog. Baseline of 3 is appropriate given high coverage.

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?

States it returns opening hours for one venue, specifying it's catalog data from the Dim Hour catalog. Clear and specific, but doesn't explicitly differentiate from sibling tools like get_venue or search_venues, though the purpose is unambiguous.

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?

No explicit guidance on when to use this tool vs alternatives. It implies it's for opening hours, but doesn't mention using search_venues to find id or get_venue for broader venue details. The schema references id from search_venues, but the description itself lacks routing context.

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