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

No annotations exist, so the description carries the full behavioral burden. It implies a mutation (registering an identity) but says nothing about whether re-registration is allowed, whether the registration is permanent/irreversible, what error conditions exist, or what the response returns. Only the signing prerequisite is disclosed.

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?

Two short sentences, front-loading the action and following with the prerequisite. Efficient, though 'whose payload accepts the responsibility statement' is awkwardly worded and slightly obscures rather than clarifies.

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 3-required-parameter mutation with no annotations and no output schema, the description covers the key prerequisite but leaves the payload's actual contents underspecified. The outbound to get_signing_guide partly compensates, but an agent still cannot construct a valid payload from this definition alone.

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 baseline is 3. The description adds that the payload carries a responsibility statement, which is meaningful beyond the schema's 'Signed payload object', but it does not enumerate the required payload fields despite the nested object being open-ended.

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 concrete verb and resource: register an AI identity by submitting a signed envelope. It distinguishes itself from siblings like list_agents and verify_agent_domain by focusing on the registration act, though the phrasing 'payload accepts the responsibility statement' is vague about what the payload must contain.

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?

Explicitly gives the prerequisite ordering: 'Call get_signing_guide first.' That is clear actionable context. It does not say when not to call this (e.g., re-registration after already registered) or point to alternatives, so it stops short of a 5.

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