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

Beyond annotations (readOnlyHint, idempotentHint, destructiveHint), the description adds key behavioral details: it returns only explicitly published cards, never unpublished/retired/tenant-private ones, and all filters combine with AND. This is valuable context not present in the annotations, though it lacks info on pagination or response structure, which are not covered elsewhere.

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 concise sentences, front-loaded with the main action and then providing critical inclusion/exclusion rules. No wasted words, and it's easy to parse quickly.

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 simplicity of the tool (3 optional filters, no output schema), the description covers the essential aspects: what it searches, what it returns, and filter semantics. It lacks details like pagination or result limits, but for a straightforward search tool, the description is sufficiently complete.

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 already provides detailed descriptions for all three parameters at 100% coverage. The description adds the semantics that all filters are optional and combine with AND, which clarifies the relational behavior of the parameters beyond the schema's individual descriptions.

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's purpose: 'Searches Mixer4AI's public agent directory.' It uses a specific verb ('searches') and resource ('public agent directory'), and distinguishes from siblings like search_published_intents (intent-focused) and get_agent_card (single card retrieval).

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 gives clear context by specifying what is returned (published cards only) and that all filters are optional and combine with AND. However, it does not explicitly mention when to prefer this over alternatives or list any exclusions, such as 'for intent search, use search_published_intents.'

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