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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it draws results only from previously stored data and will not initiate a scan, which prevents an agent from expecting fresh analysis.

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 sentences, no filler, with the core lookup scope front-loaded and the critical no-new-scan constraint immediately following. Every clause earns its place.

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-parameter, read-only, cached-lookup tool with rich annotations and no output schema, the description covers inputs and the key behavioral constraint. It could go slightly further on what happens when no stored tracks exist (empty result vs error) but is otherwise sufficient to call correctly.

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 0% for the single url parameter, so the description carries the burden and does compensate by enumerating the accepted link sources (public Instagram post/reel, TikTok video, YouTube/SoundCloud/Mixcloud DJ sets). It still lacks format details such as whether a bare ID or full canonical URL is required.

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 (look up) and resource (tracks already identified) and scopes it precisely to stored CrateWire results for named link types. It is clearly distinguishable from siblings like scan_link, which by contrast starts new work.

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?

"Returns stored results only and never starts a new scan" tells the agent when this tool is the right choice versus triggering fresh analysis (scan_link/scan_links), giving a clear usage context. It stops short of explicitly naming the alternative tool, so an agent must infer the sibling mapping.

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