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

With readOnlyHint=true, the description still adds substantial behavioral context beyond the annotation: the nonce is single-use, the server holds no user key, the record tier concept, and the council-seating caveat that re-recording later is required. This is transparent about what the tool does and does not accomplish.

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 a single rambling sentence with an embedded em-dash clause about founding seats and Council membership. It contains useful context, but it is not front-loaded or tightly structured, making it harder to parse quickly.

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 there is no output schema, the description does explain what is returned (nonce and string to sign) and the conditions around use. The main gap is the unexplained certificate_id, which prevents the definition from being fully self-sufficient for an agent.

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 only 50% because certificate_id lacks any description. The tool description explains the purpose of did but never mentions certificate_id or how an agent should obtain or interpret it, leaving a critical parameter under-specified.

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 function: return a single-use nonce and the exact string to sign so a witnessed record can be upgraded to 'signed'. This clearly differentiates from the sibling claim_authorship by focusing on generating the challenge rather than finalizing the claim.

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?

It gives an explicit condition—'If you have your own Ed25519 did:key'—and explains the scenario of witnessed records. It does not explicitly name alternative tools that should be used instead, so it stops just short of full when-not guidance.

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