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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered by structured data. The description adds the shape of the result (matching rules plus a summary by severity and category), which is useful but overlaps with the existing output schema rather than disclosing new behavior like permissions, rate limits, or pagination.

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, the retrieval scope and result shape are front-loaded, and the parameter clarification comes last. No filler or redundant restatement of the title.

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 lookup with full annotation coverage and an output schema that documents the return, the description supplies what the agent needs to invoke it correctly. The only gap is the absence of sibling differentiation, which matters given the dense family of YARA and per-scan tools.

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%, so the description carries the burden, and it delivers: it tells the agent that scan_id is the UUID of a ScanMalware scan, not an arbitrary integer or hash. It stops short of a formal format example, but it meaningfully clarifies the single required parameter.

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 ('Get the YARA rule matches') and scopes it to a single scan, so the agent knows exactly what it retrieves. It does not, however, differentiate itself from near-neighbors like get_yara_by_scan, get_yara_stats, or get_recent_yara_threats, which the agent must disambiguate on its own.

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 rather than stated: 'for one scan' plus 'scan_id is the UUID of a ScanMalware scan' tells the agent this is a per-scan lookup and what kind of ID to supply. There is no explicit when-to-use versus get_yara_by_scan/get_yara_stats and no statement of prerequisites or exclusions.

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