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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower. The description adds genuinely useful disclosure beyond annotations: counts are static public catalogue snapshots rather than live tracking, and the UCS database stopped updating in 2023-05, so source vintage must be checked.

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?

Explicitly labeled Purpose/Guidelines/Limits/Ex sections keep it front-loaded and scannable, with no wasted sentences. The template phrasing is slightly mechanical but every line carries information.

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 an output schema present, return format need not be explained. The description covers scope, usage, and the important data-vintage caveat, leaving only alternative-tool routing unspecified.

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% and the description adds no parameter-level detail (keyword semantics, language behavior, format tradeoffs) beyond what the schema already documents. Baseline 3 applies when the schema carries the full burden.

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 a specific verb+resource (constellation status) and enumerates exactly what is returned: in-orbit counts for Starlink, Qianfan, Guowang, OneWeb and Amazon Leo, annual launch totals, and planned sizes. This distinguishes it clearly from sibling telecom/carbon/standards tools.

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?

"use for constellation scale questions" gives clear context for when to reach for it. However, it names no alternative tool and gives no exclusion condition, which is what would be needed for a 5.

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