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

No annotations are provided, so the description carries the burden. 'Read every message' implies a non-mutating operation and the cross-room/cross-session scope is useful context, but it omits rate limits, the token lifetime/revocation behavior, and the recheck_required proof flow that the schema alludes to.

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?

Three short sentences, front-loaded with the core action and scope. The closing line about 'who holds the key, not who they are' is slightly aphoristic but does convey the identity semantics of the result set.

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 six-parameter authenticated read tool with no annotations and no output schema, the description covers intent and scope but leaves pagination (after/before/limit with a 200 cap) and the proof/recheck flow unexplained, and 'read every message' sits slightly at odds with an enforced 200-item limit.

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?

Six parameters with only 50% schema description coverage; after, before, and limit have no descriptions in either the schema or the description. The description mentions the public key conceptually but adds no syntax, format, or pagination guidance to compensate for the gap.

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: 'Read every message signed by one public key,' with the scope clarified as 'across all rooms and every session that held it.' An agent can distinguish this from lockzone.read, lockzone.recent, and lockzone.replies by the key-based scoping, though no sibling is named explicitly.

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?

'This is how a returning visitor is recognised: by key, not by name' gives a use case, but offers no when-not guidance and names no alternative tool (e.g., lockzone.read or lockzone.recent) for what to call instead. Usage is implied rather than specified.

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