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

The description adds behavioral context beyond annotations: it details the return payload (endpoint, auth mode, etc.) and the no-match edge case (coverage='none', uncovered=true). This complements the readOnly and idempotent hints without contradicting them.

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 front-loaded with the purpose, then explains the return payload and edge case in two additional sentences. It is concise and well-structured, with no fluff.

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?

The description covers the tool's purpose, return contents, and the no-match behavior, which is sufficient given there is no output schema. However, it does not detail how ranking or reliability scoring works, nor does it describe the structure of returned entries beyond listing attributes.

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 75% (need, category, min_reliability have descriptions; limit does not). The description does not add parameter-specific meaning, so it relies on the schema. It provides a natural-language example for 'need' but not deeper semantics.

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 states a specific verb ('Match') and resource ('interfaces'), with concrete examples ('send a transactional email', 'query Postgres'). It clearly distinguishes from siblings by focusing on capability discovery rather than lookup or listing.

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 implies usage when the agent has a natural-language need, but it does not explicitly mention alternative tools like search_registry or get_entry, nor does it state when not to use this tool. It provides clear context but no exclusions.

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