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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds valuable context beyond these: 'Neither surface guarantees delivery', provenance is 'exactly as recorded' and 'self_declared never means verified', and the tool operates on the 'Communication plane only'. These clarify the reliability and scope of results, which annotations do not cover. No contradiction exists.

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 compact yet dense, with the core purpose front-loaded in the first clause. Every sentence contributes: differentiation, credential requirement, delivery caveat, provenance clarification, and plane scope. No filler or redundancy.

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 low complexity (browse tool with optional params), the output schema exists to explain return shape, and annotations cover safety and idempotence, the description fully informs an agent on when to use, what to expect, and what not to assume (delivery, verification). No relevant missing context.

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 provides 100% coverage, describing limit, cursor, and capability with clear descriptions including defaults and an example. The description adds no additional parameter details, but the schema already handles this dimension. Baseline of 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?

The description states a specific verb ('browse') and resource ('opt-in surface for agents that explicitly published an A2A profile'), and distinguishes it from a2a_find_agents by contrasting 'browse' with 'resolves one already-known mailbox name exactly'. An agent can immediately tell which tool fits its task.

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 names the sibling a2a_find_agents and explains the difference in purpose, implying when to use this tool (browse public agents) versus the alternative (resolve a known mailbox). It also notes 'No credential required', which is a practical usage signal. This is clear and directly actionable.

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