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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is known. The description adds that it 'Uses metered access' and 'does not modify source data,' which clarifies operational behavior. It could mention pagination or result format, but with output schema present, the description adds sufficient value above annotations to warrant a 4.

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 three sentences, each adding distinct value: purpose, usage patterns, and an alternative tool reference. It is concise and front-loaded, with no redundant or filler content.

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?

Given the tool's simplicity (2 optional params) and rich annotations and output schema, the description covers purpose, usage modes, and behavioral notes. It also provides a pointer to a sibling tool. No critical gaps.

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% (both params described). The description adds semantic nuance: 'Pass service alone to list its indexed endpoints, add query to narrow by path or operation, or use query alone across services' explains how params combine, which goes beyond schema descriptions. This justifies a slight upgrade from baseline 3 to 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 clearly states the tool searches for exact request and response schemas for third-party API endpoints, using a specific verb ('Search') and resource ('schemas'). It distinguishes from siblings like factreason_integration_brief by explicitly naming an alternative, making the scope unambiguous.

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 provides explicit usage patterns: 'Pass service alone to list its indexed endpoints, add query to narrow by path or operation, or use query alone across services' and recommends 'Prefer factreason_integration_brief for one callable request.' This gives clear when-to-use and when-not-to-use guidance with a named alternative.

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