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

With no annotations, the description supplies the safety profile itself (read-only) plus a non-obvious data-source caveat: TSDR when a free key is set, otherwise the public Trademark Search record, which implies possible differences in freshness or coverage. It also enumerates the returned fields. It stops short of stating behavior on a missing/invalid number or how latency/rate limits differ between the two backends.

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 dense paragraph that front-loads the purpose and identifier format before the routing rule. Some waste in repeating the sn/rn examples already in the schema, but nothing extraneous beyond that.

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 single-parameter lookup with no output schema, the description covers identity, scope, data source, and return contents, which is nearly everything needed. Only not-found/error handling is left unstated.

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% and the id parameter's description already covers sn/rn prefixes and the bare-number fallback, so the description's format examples largely restate structured data. Baseline 3 applies — no additional syntax, validation, or normalization behavior is added.

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 and resource — authoritative status lookup for a single mark — and pins the identifier space (serial or registration number). It explicitly distinguishes itself from name-based searching, so an agent can route correctly without opening either schema.

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?

Names the precondition (you already have an sn/rn, e.g. from a screen_trademark hit) and the exclusion (not for searching by name — use screen_trademark). Both when-to-use and the alternative are stated outright.

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