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

Annotations already declare readOnlyHint and idempotentHint, covering safety. The description adds valuable behavioral context beyond annotations: it states the result is sorted by track record (successfulIngestionCount, lastIngestionAt) with a computed recommendation score, and that it degrades to an empty array on backend error. This goes beyond the structured 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?

The description is compact at four sentences, each earning its place: purpose, return characteristics, usage guide, and parameter/behavior details. It is front-loaded with the core purpose and avoids redundant or fluffy language.

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 tool with two optional params and no output schema, the description covers purpose, usage, parameters, and error behavior. However, it does not explain how the merchant is identified (no merchant parameter in schema), which could be ambiguous. Still, the overall coverage is strong for the complexity level.

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 must compensate. It does so by naming both optional filters, listing the archetype enum values (stord, flexport, shipbob, generic), specifying the limit range (1-100), and adding the default limit of 10. This fully clarifies parameter meaning beyond the raw 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?

The description clearly states the tool 'Get an ordered list of recommended service providers (WMS, 3PL, fulfillment partners) for a merchant.' This uses a specific verb ('Get'), identifies the resource ('service providers'), and scopes it to merchant needs. It also distinguishes from sibling tools like recommend_lender by explicitly naming WMS/3PL/fulfillment partners.

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?

The description provides explicit when-to-use context: 'Use this when an agent needs to route a merchant to an appropriate WMS/3PL based on operational capability.' It gives a concrete example. However, it does not explicitly mention when not to use it or alternative tools, so it lacks the full when/when-not/alternatives structure for a 5.

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