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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the baseline is met. The description adds genuinely new behavioral context: only cards explicitly published by their owning principal are returned, and unpublished, retired, or tenant-private cards are excluded. Return shape and result limits are not described, keeping this below a 5.

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?

Two front-loaded sentences with no filler; the visibility guarantee comes immediately after the purpose. Slightly dense phrasing ('Returns only agent cards their owning principal has explicitly published') costs some readability but not length.

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?

With no output schema, the description partially compensates by explaining what kinds of cards are returned and that all filters are optional, which is enough to call the tool correctly. It omits result ordering, pagination, and whether an empty filter search returns the whole directory, which an agent would want to know.

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%, so each parameter is already documented with its meaning and 'omit for no filter' default. The description's only added semantic value is that filters combine with AND, which is real but minor; it adds nothing about the intent/offer capability values beyond the schema.

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 names a specific verb and resource ('Searches Mixer4AI's public agent directory') and states the visibility rule for returned cards. It does not distinguish itself from sibling tools like find_verified_agent, get_agent_card, or search_published_intents/offers, so an agent must infer which search surface to pick.

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?

'All filters are optional and combine with AND' gives useful query-construction guidance, and the visibility sentence implies the tool is for discovery of public cards. However, there is no explicit when-to-use / when-not-to-use guidance and no pointer to the closely related sibling search tools.

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