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

No annotations are provided, so the description carries the full burden. It clearly discloses full server-side pagination, the return of scanned/capReached so 'no matches' answers are trustworthy, and case-insensitive substring matching. While it doesn't explicitly state read-only status, the verb 'search' implies a non-mutating operation, and no side effects are relevant. It doesn't cover rate limits or auth, but that is beyond expected scope for a search tool.

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 sentences, each earning its place: the first states the core action, the second gives use-case-specific guidance with an explicit alternative, and the third explains result fields and a performance tip. There is no fluff, and the most important information is front-loaded.

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?

Despite lacking an output schema and annotations, the description adequately covers the tool's behavior, including the trustworthiness of 'no matches' via scanned/capReached and the effect of optional filters. It could have listed the exact return fields when compact=false, but mentioning 'all 7 fields' and the compact option gives sufficient context for correct invocation.

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?

The input schema already describes every parameter (100% coverage), providing baseline 3. The description adds practical meaning beyond the schema by explaining why to use optional filters: 'Narrow with sectionId/suiteId to scan less.' This gives agents guidance on reducing resource usage, which is not inferable from 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?

The description opens with a specific verb+resource: 'Search a TestRail project for cases whose title contains the given text (case-insensitive substring), walking ALL pages server-side.' It explicitly differentiates from the sibling testrail_list_cases by naming it and stating the exact use case (checking for existing cases before create_case), making the tool's role unmistakable.

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?

Provides direct, actionable guidance: 'USE THIS — not testrail_list_cases — to check whether a case already exists before calling testrail_create_case, because it cannot be fooled by a truncated page.' It also advises narrowing the scan with sectionId/suiteId, covering both why and how to use the tool effectively.

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