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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), the description discloses privacy behavior ('Only the hash is sent: Proofestry never sees the content'), return contents (token + record id), and failure/cost semantics ('A failure at the authority is a 5xx and is never charged', '0.01 USDC per hash'). That is substantial added context; the only gap is that non-idempotency is not spelled out (repeated calls create separate paid records).

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 core action and its effect are front-loaded, and the privacy, return-value, error, and pricing sentences each carry useful information. The trailing 'MCP tool: `timestamp`.' is pure filler, and the length is near the upper bound for a two-parameter tool.

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?

There is no output schema, but the description compensates by naming the return values (RFC 3161 token, verifiable with `openssl ts -verify`, plus a record id) and by covering cost and failure behavior. For a two-parameter, non-destructive tool this leaves nothing an agent needs 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 description coverage is 100%, so both `sha256` and `label` are already documented in the schema, and the description's privacy note on the hash duplicates the schema text. The description adds no new meaning for `label` or for the required hex format, so the baseline 3 applies.

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 ('Obtains an RFC 3161 timestamp token for a SHA-256 hash from a public timestamp authority and stores it'), plus the effect of storing it. It is clear what the tool produces, but it never names the sibling `verify_timestamp` or otherwise explicitly distinguishes itself from the other Proofestry tools.

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?

Usage is implied by the statement 'A timestamp proves the hash existed then, not who made the content or that it is true', which frames the appropriate use case. However, there is no explicit when-to-use/when-not-to-use instruction and no routing to alternatives such as `verify_timestamp` for checking an existing token.

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