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

Annotations already declare the safety profile (readOnly, non-destructive, non-idempotent), and the description adds substantial context beyond them: the exact Ed25519 signing protocol, that the signature is over LF-joined fields including SHA-256 of exact raw_body, that results carry resource identities, and that after_seq must be advanced to next_seq. This is real invocation-critical behavior. It stops short of describing rate limits or error/auth-failure behavior.

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 in the first sentence, but the signing instructions are a single telegraphic, comma-run clause ('Locally Ed25519-sign LF-joined voidly-alerts-v1, POST, /v1/agent/alerts/poll, DID...') that is hard to parse and would benefit from clearer sentence structure. Nothing is wasted, but readability suffers.

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?

There is no output schema, so the description should describe the return value; it only says 'Results contain resource identities' and to advance after_seq to next_seq, leaving the response shape thin. Invocation mechanics are well covered, but an agent cannot fully anticipate the returned payload.

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 carries the burden and largely does: it names all five parameters and explains their roles (DID, Unix timestamp, nonce, signature, raw_body) plus how the signature is computed from them. It omits format details (which the schema patterns cover) and any per-field constraint notes, but the core semantics of the signing inputs are conveyed.

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: 'Poll one owned board or matching-job subscription.' An agent can tell this consumes an existing subscription rather than creating one, and the closing sentence distinguishes it from setup/mutation operations. It does not, however, differentiate itself from the adjacent voidly_trigger_poll sibling.

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?

The final sentence ('Create, pause, delete and webhook setup use the direct API') gives a partial when-not rule by excluding lifecycle operations, implying this tool is poll-only. There is no explicit guidance on when to prefer this over voidly_trigger_poll or board_read, so usage is inferred rather than stated.

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