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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false), and the description adds genuinely non-structured facts: no signature or auth is needed, the call is free, it completes in a single round trip, and the information is recorded but never verified or privileged. That is meaningful disclosure beyond the annotations.

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?

Purpose is front-loaded, but the prose is padded and partly redundant: 'Optional' in the first sentence is restated by 'Every field is optional; an empty call still greets you' at the end. The poetic phrasing is charming but costs tokens without adding selection signal.

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 zero-required, 6-parameter tool with no output schema, the description covers optionality, the absence of auth/verification, and what comes back ('where to start', the full path for the declared intent). Minor gap: it does not say whether repeat handshakes overwrite or accumulate, which is relevant given idempotentHint=false.

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 text is rich (including the intent enum and its legacy aliases), so the schema does the heavy lifting. The description contributes a narrative mapping ('who you are, where you came from, what you are here to do') and the optionality note, but no syntax or format detail beyond the schema.

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 action (introduce yourself, receive where to start) with an explicit scope note that nothing is verified or granted, which implicitly separates it from register_agent. The verb is metaphorical ('handshake') but the body of the description resolves what it actually does.

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?

'Optional, unsigned, free, and answered in one call' plus 'Without it this hub describes you by your address and your HTTP library' tells the agent exactly what it gains and what the fallback is. It stops short of naming an alternative sibling (e.g. register_agent) for when a verified identity is needed.

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