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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: the fallback from manifest to on-chain resolver, and the meaning of verification and manifest status fields. This goes beyond the annotations without contradicting them.

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?

Three sentences, each earning its place: the first states the core function, the second explains the resolution order, and the third disambiguates two important result fields. No fluff or repetition of schema content.

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 read-only lookup tool with two well-documented parameters and no output schema, the description covers the essential behavior: what is returned, how the data is sourced, and how to interpret edge cases. It could mention the exact shape of the response, but the absence of an output schema makes that a minor gap.

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 the schema already documents both parameters well. The description adds context about what the endpoint URL is used for and the pricing model, but it does not add new parameter-level detail beyond the schema. 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?

The description states a specific verb ('Get'), a clear resource ('an agent's endpoint URL'), and the key dimensions (protocol and pricing model). It also distinguishes itself from siblings by naming the manifest verification and resolver fallback behavior, which sets it apart from agt_resolve and agt_manifest.

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 explains the resolution strategy (prefers verified manifest, falls back to on-chain resolver) and clarifies the meaning of `verified: false` and `manifestStatus: "unavailable"`, which helps an agent interpret results. It does not explicitly name sibling tools or state when to use agt_resolve instead, but the context is clear enough for selection.

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