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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds behavioral context by detailing the return data (start/max/end times, elevation, azimuths, brightness magnitude, duration) and explaining the visual pass definition, which goes beyond the annotations without contradicting them.

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 three concise sentences plus an example, front-loading the core purpose. Every sentence contributes: definition, return values, and a usage example. No redundant or filler content.

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?

With no output schema, the description appropriately enumerates the returned fields and provides a concrete example. It covers the essential context for a satellite pass query, though it does not address edge cases like no passes found or rate-limit behavior, but those are partially handled by annotations and schema.

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 100% with descriptive parameter definitions. The description complements this by providing a real-world example (ISS with lat/lon) and clarifying the meaning of 'visual passes' in relation to parameters like min_visibility. This adds value beyond the schema alone.

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 resource ('satellite visual passes'), clearly defining the scope as naked-eye visibility for an observer location. It distinguishes from sibling tools like get_positions by emphasizing 'bright, sunlit passes against a dark sky' and includes a concrete use case ('when can I see the ISS pass over?').

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 a clear use case ('when can I see the ISS pass over?') and a concrete example call, establishing context for when to use the tool. However, it does not explicitly mention alternatives or when not to use it, such as differentiating from get_positions or whats_above.

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