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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context: results are ordered newest-after-a-sequence-number and the response includes a head hash and public key. It omits pagination behavior, the meaning/default of limit, and any rate-limit or auth expectations.

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?

A single front-loaded sentence with no filler; the cursor semantics are stated immediately. Slightly awkward that return values ('head hash and public key') are packed into the same clause as the read operation, which can read as more input than output.

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?

For a two-parameter read-only tool with no output schema, the description covers the log cursor and names two returned fields, which is reasonable. It still leaves 'limit' entirely undefined and gives no sense of return shape or how to use the head hash for verification, so an agent cannot call it fully confidently.

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% for two parameters, so the description carries the burden. It clarifies 'after' as a sequence number acting as an incremental cursor, which is useful, but says nothing about 'limit' — no default, no maximum, no effect on the response — leaving half the parameters undocumented.

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?

States a specific verb (Read) and resource (the public stamp log), plus what comes back (head hash and public key), which distinguishes it from the sibling write/verify tools countersign_stamp and countersign_verify. The purpose is clear, though it never explicitly contrasts itself with those siblings.

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 parenthetical 'newest after a sequence number' implies incremental polling of the log, but the description gives no when-to-use, when-not-to-use, or alternative-tool guidance despite having countersign_verify and countersign_stamp as plausible neighbors. An agent must infer the workflow from context alone.

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