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

Annotations already document read-only, idempotent, and non-destructive behavior. The description adds the return field list, which is useful, but does not disclose additional behavioral traits such as whether the search covers past/upcoming launches, pagination, or rate limits. With annotations covering safety, this meets the baseline.

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 that front-load the core action and resource, list return fields, and avoid redundant wording. Highly 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?

The description, combined with full schema coverage, output schema, and annotations, provides sufficient information for a simple search tool. However, it leaves ambiguity about whether the search includes past, upcoming, or both types of launches—a relevant detail given the presence of dedicated past/upcoming siblings.

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 descriptions cover both parameters completely (100% coverage) with examples and defaults. The tool description's mention of 'rocket name, mission, agency' partially overlaps with the schema's examples, adding marginal semantic value beyond the schema.

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 action (search), the resource (launches), and the search criteria (keyword: rocket name, mission, agency). It also lists the return fields, distinguishing it from sibling tools like get_launch which appear to retrieve specific launches by ID.

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?

Provides clear context for when to use the tool (when you have a keyword to search launches) and subtly differentiates from specific retrieval siblings, but does not explicitly name alternatives or state when not to use it. The context is clear enough for most use cases.

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