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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses the signature state machine (`signed`, `no_key`, `misconfigured`), the verification requirement, the `unavailable` edge case, and the fact that no key is needed. This is rich, non-obvious, and directly useful to the agent.

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 manifest contents, then covers the signature-branching behavior, edge case, and access model. Every sentence adds distillable information: the URL mirror, signature verification, `unavailable` behavior, and public availability are all relevant and not redundant.

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 must explain what the response contains and how to interpret it. It enumerates the manifest sections, explains `signature_state` handling, covers the unsigned/misconfigured cases, and states auth requirements. An agent has enough information to invoke and consume this tool correctly.

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?

There are zero parameters, so there is nothing for the description to clarify about inputs. The baseline of 4 applies because no parameter compensation is needed, and the description instead clarifies the output content, which is the only meaningful semantic surface here.

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 identifies the tool as returning a JSON manifest containing the fee wallet, every fee, rate limits, api_version, tool list, and deprecation schedule. It names exactly what is exposed and presents it as a single JSON object, making the purpose unmistakable and distinct from sibling tools.

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: it is a public, key-free, read-only manifest, and it explains how to branch on `signature_state` when using the response. It does not explicitly name alternative tools or state when not to use it, but for a zero-parameter manifest endpoint this is sufficient direction.

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