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

Annotations already declare non-idempotent, open-world, non-destructive write behavior, and the description explains WHY: a randomized commitment is submitted to public calendars, results come back as pending_calendar, and it fails explicitly when calendars are unavailable. It also discloses cost (250 sats L402, X-L402-Batch-Size: 100 for 25000 sats), which is nowhere in structured fields.

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?

Content is dense and front-loaded into PURPOSE / USAGE / BEHAVIOR blocks, and essentially every sentence carries non-redundant information. The ALL-CAPS section labels and the pricing tail make it slightly heavier than it needs to be, but nothing is padding.

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?

An output schema exists, so return values need no explanation, yet the description still tells the agent what to do with otsProofHex and how the call can fail. Cost, batching, and failure modes are all covered, leaving no operational gap.

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% and the single hash parameter is fully documented in the schema, so the baseline is 3. The description's 'one 64-character hexadecimal hash' simply restates that; the extra value it adds (decode otsProofHex) concerns the return value, not the parameter.

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?

Names a precise verb+resource+mechanism: create a detached OpenTimestamps .ots receipt for an agent-supplied SHA256 digest via public calendars. It also draws an explicit boundary against proof.verify and against treating the receipt as Bitcoin confirmation, which separates it from the sibling verify tool.

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?

States exactly when NOT to use it ('not immediate Bitcoin confirmation', 'not a replacement for proof.verify') and the input contract ('submit exactly one 64-character hexadecimal hash'). This is explicit routing rather than implied usage.

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