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

With no annotations, the description carries the full disclosure burden. It usefully reveals the cryptographic contract (Ed25519 signature in, token out), which is genuine behavioral signal beyond a bare name. However, it omits the prerequisite handshake state, authentication/permission requirements, and whether the token is single-use or expiring.

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?

A single compact sentence that front-loads the action and the payload/return. It is efficient, though the dangling `sign` reference wastes a few words on ambiguity.

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 handshake-completion tool with no annotations, no output schema, and 0% parameter documentation, the description is too thin: it omits the prerequisite challenge step, the meaning of `id`, and any failure modes. An agent cannot reliably invoke it from this 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 0%, so the description must compensate and largely does not. It hints that the payload is an Ed25519 signature but refers to `sign` (not a parameter), and never explains what `id` identifies or how `sig` relates to it.

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?

It names a verb ('Finish', 'send', 'take') and resources ('key return', 'token'), but the phrase 'key return' is idiosyncratic and the description references `sign`, which is not a parameter name (params are id and sig), leaving the exact operation ambiguous. It does not name the obvious sibling haven_key_challenge that this presumably completes, so differentiation is left to inference.

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?

There is no when-to-use statement, no mention that a prior haven_key_challenge must have been obtained, and no comparison to any alternative tool. An agent can only guess the preconditions from the word 'Finish'.

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