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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds non-obvious behavior: it walks ALL pages server-side and returns scanned/capReached so a 'no matches' result is trustworthy. That pagination/trust disclosure is exactly the value beyond structured fields.

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?

Three dense sentences, front-loaded with purpose then routing then scope-narrowing; no sentence is filler. Sizing is appropriate for a tool with a subtle correctness advantage over its sibling.

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?

No output schema exists, and the description compensates by describing the return shape (only matching cases plus scanned/capReached). Combined with the routing and narrowing guidance, an agent has everything needed to call and interpret 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 coverage is 100%, so the baseline is 3, but the description adds a reason beyond the schema's terse 'Optional suite scope'/'Optional section scope' by explaining that sectionId/suiteId narrow the scan. It also reinforces the substring semantics of query, though that partly repeats the schema.

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 (search/find), resource (TestRail cases), and matching semantics (case-insensitive substring on titles), and explicitly distinguishes itself from testrail_list_cases. An agent can identify the right tool without opening any 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?

Gives explicit routing: 'USE THIS — not testrail_list_cases — to check whether a case already exists before calling testrail_create_case,' plus the reason (not fooled by a truncated page) and a narrowing tip. Both the when and the alternative are named.

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