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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds meaningful context beyond that: it returns 'top-N most relevant tools with names, descriptions, and full input schemas (with curated examples)' and emphasizes 'ready to call directly, no second schema lookup needed.' This gives the agent confidence about the return format and saves a step, which is valuable behavioral disclosure.

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 core purpose and is composed of three sentences. The long enumeration of domains is purposeful for a discovery tool, but it makes the description slightly less tight than the two-sentence ideal. Still, each element earns its place and there is no filler.

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 role as a discovery interface and the absence of an output schema, the description covers the essentials: what it does, when to use it, and what it returns (names, descriptions, full schemas, examples). It does not address edge cases like no results, but for this complexity level, the description is sufficiently complete to guide an agent.

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 100%, with all parameters documented in the schema, including aliases and default/max values. The description itself does not add semantic meaning beyond what the schema already provides—it only repeats the notion of describing a task. Per the baseline for high schema coverage, this is a 3.

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 opens with a specific verb+resource: 'Find tools by describing the data or task.' It further clarifies the action set (browse, search, look up, discover) and enumerates the covered domains, making it unmistakable what this tool does. It also distinguishes itself from siblings by stating 'Call this FIRST... when you have many tools available... not just one answer,' which positions it as the discovery entry point rather than a direct execution tool.

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 explicitly states when to use the tool ('Use when you need to browse, search, look up, or discover what tools exist') and gives a strong contextual cue ('Call this FIRST when you have many tools available'). However, it lacks an explicit when-not or reference to alternative tools by name, so it misses the full 'when/when-not/alternatives' guidance that would earn a 5.

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