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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: it previews results, provides breakdowns by mark type/standard character/class, reports data completeness, and supports combining claimed-color criteria with attributes. It also clarifies that color-alone counts are out of scope, which is a behavioral boundary not visible in the schema. Minor gap: it doesn't describe pagination or the exact shape of the preview, but the annotations carry the safety burden.

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 with no filler. The first sentence front-loads the core function (counts/previews by attributes) and the breakdowns, and the second sentence adds the color-combination capability and scope exclusions. Every clause earns its place, and the scope exclusion is concise rather than verbose.

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 read-only analytics tool with 9 optional parameters and no output schema, the description covers the core purpose, the attribute dimensions, the breakdowns, data-completeness reporting, and scope exclusions. It doesn't describe the return format or pagination, but since there is no output schema, a brief note on what the preview contains would strengthen it. The annotations cover safety, and the parameter semantics are mostly inferable from the schema enums and defaults. Overall, it's nearly complete for an agent to decide whether to invoke it.

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 only 44%, so the description must compensate for undocumented parameters. The description adds meaning by explaining that attributes (drawing type, standard-character claim, Nice class, status) can be combined, and that claimed-color criteria can be combined with these attributes. It also clarifies the scope of color parameters (exact canonical shades vs normalized families) indirectly. However, it doesn't explain the semantics of class_match_mode, color_match_mode, or limit beyond what the schema already provides, and it doesn't detail how the parameters map to the breakdowns.

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 states a specific verb ('Counts and previews'), a clear resource (USPTO marks by record attributes), and enumerates the exact attribute dimensions (drawing type, standard-character claim, Nice class, status) plus combinations. It also explicitly names what is outside its scope (color-alone counts, rankings, lists, color vocabulary), which distinguishes it from siblings like search_claimed_colors and count_filings_by_period.

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?

The description clearly implies when to use this tool: when the agent needs aggregate counts/previews of USPTO marks filtered by record attributes, with breakdowns. It explicitly excludes color-alone counts, rankings, lists, and color vocabulary, which routes the agent away from this tool for those needs. However, it does not name specific sibling alternatives (e.g., search_claimed_colors, count_filings_by_period) or state explicit when-not-to-use conditions beyond the scope exclusions.

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