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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds real behavioral value the annotations do not: the expected input format (SC-2026-123456) and the fact that a successful check returns song and license coverage, not just a boolean.

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?

One sentence, front-loaded with the action and the identifier, with the return scope appended. Every clause earns its place and nothing is padded.

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 one-param read-only lookup with no output schema, the description covers the action, the input format, and the nature of the result. It does not mention what happens on an invalid/unknown certificate or whether the number is case-sensitive, which would round it out.

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 0%, so the description must carry the parameter. It supplies the exact certificate format (SC-2026-123456), which is the single most useful thing an agent needs to avoid a malformed call, well above the baseline for a one-parameter tool.

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 (check/verify) and resource (Starchild license certificate number), and adds concrete scope: whether the certificate is genuine and which song/license it covers. No sibling tool does certificate verification, so it is clearly distinguishable from get_song, license_options, etc.

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?

Usage is implied — verify a certificate you already hold — but there is no explicit when-to-use, when-not-to-use, or pointer to an alternative such as license_options for browsing rather than verifying. Adequate but with a clear gap.

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