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

Annotations already mark read-only/idempotent, and the description reaffirms them while adding non-structural details: 10-match cap, 24-hour cache, and verified data source. These details help an agent predict latency and freshness without contradicting the annotations.

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?

Front-loaded with the core purpose and scoped to the point of use. It is dense but not bloated, though the feedback-instruction block at the end is long generic boilerplate that adds length.

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 simple 3-parameter search with an output schema, the description covers return content, result cap, cache behavior, source, and the fallback path if the result is inadequate. Nothing material is missing.

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%, so baseline is 3; the description goes beyond by giving inline examples for keywords, enumerating jurisdiction values with default, and specifying ISO 8601 format plus default behavior for date_from. This adds practical value over the schema alone.

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 the action ('Search patents by keyword') with explicit resource and scope (EPO, USPTO, WIPO). The contrast with legal_fetch_patent_by_number removes any ambiguity about what this tool is for.

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?

Explicitly sets the condition for use: finding prior art or exploring a technology landscape without a specific number. It also names the alternative (legal_fetch_patent_by_number) for when a patent number is already known, and points to report_feedback for gap handling.

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