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

With no annotations provided, the description carries the transparency burden. It discloses that this is a search operation, that results are ranked by measured reliability, and it defines what the 'deep' and 'shallow' tier filters mean. It does not mention output format, pagination, or side effects, but the essential behavior is clearly conveyed.

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?

The description is a single, well-structured sentence that front-loads the core purpose, then provides use-case context and optional filtering details. There is no repetition of schema information and no filler. Every clause adds value.

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 search tool with three flat parameters and no output schema, the description covers the search intent, ranking behavior, and tier filtering. It does not describe the exact output shape, but the phrase 'options ranked by measured reliability' gives a reasonable expectation. A sibling-tool mention would make it more complete.

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 covers 67% of parameters with descriptions, and the tool description adds meaningful context: it explains the query purpose and defines the tier values. The 'limit' parameter lacks description, though its min/max constraints are visible in the schema. The added tier definitions go beyond the schema, justifying a 4.

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 uses a specific verb ('Search') and a specific resource ('Vouch's independently measured corpus of MCP tools'), clearly distinguishing this from the sibling tools vouch_check and vouch_compare. The emphasis on 'measured reliability rather than popularity' further differentiates it from generic search tools.

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?

It explicitly states when to call this tool: 'when choosing an MCP tool for a task and you want options ranked by measured reliability'. It gives clear usage context but does not name sibling alternatives or state when not to use it, so it falls short of a 5.

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