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

Beyond the readOnlyHint annotation, the description adds meaningful behavioral context: no authentication is needed, the call is repeatable without side effects, and after sealing the same read reports whether the prefix still matches. This gives an agent a fuller model of the tool's behavior.

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 description is compact and front-loaded, opening with the core action before adding workflow context. Every sentence earns its place: what is read, why to use it, what happens after sealing, and the safety/no-auth guarantee.

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?

With no output schema, the description adequately explains what the caller receives: the verbatim legacy prefix plus the digest a manifest row would seal over it. It also documents the post-sealing comparison behavior, making the tool's contract complete enough for an agent to invoke it correctly.

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 tool accepts zero parameters, so the 100% schema coverage makes parameter semantics a non-issue. The description compensates by explaining the conceptual input context (which chains and which rows are read), meeting the baseline for a parameterless tool.

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: 'Read the legacy prefix of each public chain' and clarifies exactly which rows are included ('the rows written before sealing shipped'). It also distinguishes itself as the read side of the manifest-sealing workflow from the sibling legacy_manifest_seal.

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 clearly explains when to use the tool: before publication to capture the digest off-machine, and after sealing to verify the prefix still matches. It implies the alternative is sealing rather than reading, though it does not explicitly name a sibling as the exclusion criterion.

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