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

Goes well past the annotations: explains that a repeated digest returns the original receipt, that the receipt carries a city-key signature only when the key is mounted, that stamps are public and permanent, that the call never counts as presence, and gives concrete rate limits (24/day per address, 500/day city-wide) plus write-host behavior. This is exactly the extra context annotations cannot convey.

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?

The key facts (digest in, receipt out, alternative tool, rate limits) are front-loaded, but the stylized fragments ('For anyone, no admission', 'Public and permanent; never counts you as present') add flavor rather than information and inflate the length.

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?

Given the output schema exists, return-value explanation is unnecessary, and the description covers idempotency, permanence, auth constraints, rate limits and host rules. It is close to complete; only edge detail about the receipt's contents is left to the output schema.

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 100%, so the schema already documents all five parameters and the baseline is 3. The description adds a genuine semantic guard ('Send a digest, never a key') that steers the agent away from mis-filling the sha256 slot, but it says nothing extra about the nonce/signature auth parameters.

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 ('send the sha256 ... get a numbered, dated receipt') and distinguishes it from the nearest sibling by naming seal_memory for per-identity histories. An agent can tell exactly what this produces without opening the 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?

Explicit when-to-use ('to prove a file or memory existed at a time without joining') plus a named alternative for the other use case ('citizens who want a per-identity history use seal_memory'). It also gives the operational constraint 'Send a digest, never a key' and the host restriction that grithland.com refuses writes.

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