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

With no annotations, the description does useful work by disclosing that this is a mutation ('Capture + seal'), that raw secrets are refused, and that it returns the sealed capsule plus capsule_id. It still omits permissions, idempotency, whether sealing is reversible, and what validation failures look like for a complex write operation.

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 definition is a single dense sentence that front-loads the operation and puts the key constraint about raw secrets in parentheses. It is efficient, though the density makes it slightly harder to parse than a short structured list would be.

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?

The description covers the core purpose, the POST /capsules equivalence, the secrecy constraint, and the return value, which helps because there is no output schema. For an 8-parameter nested mutation with no annotations and no schema descriptions, it still leaves important parameter and behavioral gaps.

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 carry the load. It adds meaning for several fields by naming tool contracts, credential references plus expiry, model pin, behaviour payload, and attestation-only assumptions, including the important constraint that raw secrets are refused. It does not explain summary, slept_day, or first_task_tools, so the compensation is partial.

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?

The description states a specific verb and resource: capture and seal an expectations capsule at sleep time, and explicitly equates it with POST /capsules. It is clearly a capsule-creation operation rather than a wake or list operation, though it does not call out the sibling tools by name.

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 phrase 'at sleep time' implies when this tool should be used, and 'same operation as POST /capsules' anchors it to a known API action. However, it gives no explicit when-not guidance or alternatives among the many hib_* wake/capsule siblings.

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