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

The description goes well beyond annotations by explaining privacy ('the file never leaves it'), rate limits ('Rate-limited (10/hour)'), the nature of the proof ('Proves the hash existed no later than the covering checkpoint'), and explicit disclaimers ('does NOT prove authorship'). It also discloses the receipt contents and the anchored-to-Bitcoin mechanism, giving a very clear behavioral model.

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 opening sentence immediately establishes the core purpose. Subsequent sentences incrementally add essential details (input options, return values, guarantees, limitations, rate limit, typical use) without redundancy. Every sentence carries useful information, making it dense yet digestible.

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?

Despite lacking an output schema, the description fully specifies the return value ('a receipt with the leaf index, inclusion-proof URL, an offline c2sp.org/tlog-proof bundle URL, and the witness trust policy'). It also covers privacy, proof semantics, limitations, rate limiting, and a use case, making it self-sufficient for an agent to invoke and understand the outcome.

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?

The schema already provides descriptions for both parameters (path, sha256) with 100% coverage. The description adds the either/or semantics ('pass a local file path ... or a sha256 hex string') and the detail that 'only 32 bytes reach the log,' which enriches the parameter meaning without duplicating the schema.

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 clearly states the tool's verb and resource: 'Notarize any file or hash into a public transparency log cosigned by 7 independent witnesses and anchored to Bitcoin.' It distinguishes itself from sibling tools by focusing on notarization, which is a distinct action from stamping, tracing, or verifying.

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 description provides context for when to use the tool: 'Typical use: notarize an output the moment it is produced, keep the file, hand anyone the proof URL.' It also notes a limitation ('does NOT prove authorship or that the content is true'). However, it does not explicitly mention alternatives or when not to use it, so it misses the full 5 score.

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