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

Annotations only give readOnlyHint=false, idempotentHint=false, destructiveHint=false. The description adds substantive behavior annotations don't: the exact signature payload/message format, that release is instant with no cooldown, that the handle is immediately reservable again, and the 'soft hold, not a lock' semantics versus on-chain registration. It also clarifies the claim code is never a credential.

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?

Front-loaded with the core action and the two use cases, then the auth requirement, then the outcome semantics. Dense but each clause earns its place. Slightly long given the repetition of the signature message string already in the schema, which is the only minor strip spot.

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 no-output-schema mutation with a non-obvious auth model, the description covers preconditions (bound key), the exact signing payload, the two reason paths, reversibility (immediately reservable), and race semantics against on-chain registration. Nothing an agent would need to call it correctly is missing.

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%, so the schema documents both params, giving a baseline of 3. The description adds meaning beyond the schema by spelling out what the signature is over (the canonical message string), the encoding (128-hex / 64-byte r||s raw ECDSA), and where reservation_id comes from. That is real value over the structured field.

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+resource ('Release your handle reservation early') and describes exactly what happens (same-day availability vs release+revoke). It also names the lifecycle siblings it ties into (prepare_agent_self_claim), so the agent can place it in the flow without opening another schema.

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 explicitly enumerates the two triggering conditions: 'when your human declines the spend' and 'release+revoke on compromise (e.g. a leaked claim code)'. It also states the key precondition (only the bound secp256k1 key can release) and contrasts against the always-available alternative ('a direct on-chain registerPage always wins').

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