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

Goes well beyond the readOnly/idempotent annotations by disclosing the null-signature edge case when the server has no signing key, the URL where verification keys live, and the no-token auth requirement. These are exactly the facts an agent needs before trusting the returned signature.

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?

Front-loads the return payload, then behavior, then inputs, then auth — a sensible order with no filler. Minor waste in the 'Inputs:' sentence, which duplicates the schema.

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 correctly enumerates the manifest's fields and the nullable signature, plus the key-publication endpoint. Nothing an agent needs to call it correctly or interpret the result is missing.

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 coverage is 100%, and the schema already describes slug and version including the omit-for-live behavior. The description's 'Inputs: slug, and optional version' largely restates that, adding no new syntax or format detail.

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?

States a specific verb and resource ('Returns the canonical manifest for a site version') and enumerates the payload fields, which clearly separates it from list_versions or get_site. It never names a sibling explicitly, so differentiation is inferred from content rather than stated.

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?

Clarifies the key decision point ('When version is omitted, the result is the live site') and removes an auth question with 'No token is required.' It does not say when to prefer this over list_versions or get_site, so there is clear context but no explicit exclusions.

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