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

With no annotations, the description carries the behavioral disclosure burden. It explicitly discloses a valuable trait: the search is free and does not consume credits. It also implies a read-only discovery operation, though it does not describe result shape or pagination.

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 two short sentences with no filler. The core action and resource are front-loaded, and the credit note is placed second.

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 one-parameter discovery tool, the description is nearly complete: it tells the agent what to search for and that the action is free. It stops short of describing the return format or how results connect to sibling tools like nexus_call, so it is not a 5.

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 fully documents the single parameter, query, so schema coverage is high. The description's 'matches a task' aligns with the schema but adds no additional format, length, or example guidance, so the baseline 3 is appropriate.

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?

Description states a specific verb ('Search') and resource ('HumanMirror Nexus catalog'), and clarifies that it finds a 'machine-callable tool that matches a task.' This clearly distinguishes it from sibling execution tools like nexus_call.

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 intended use case is implied: when an agent has a task and needs to find a tool, it should search the catalog. The note that the search is free adds useful context, but there is no explicit statement about when to use this versus siblings or when not to use it.

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