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

Annotations already cover readOnlyHint/idempotentHint/destructiveHint, but the description adds valuable behavior beyond them: nothing is ever deleted from the log, it still answers for retracted items, output is one line per revision ordered oldest-first, and an unknown id returns plain text 'no history for id X' rather than an error. The non-error response for unknown ids is exactly the kind of edge-case behavior an agent needs to know. No contradiction with annotations.

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?

Four dense sentences and every one earns its place: core function, sibling routing, persistence/read-only caveat, and output format. Slightly cryptic 'Code lane:' prefix and slightly metaphorical 'walks one item's whole life' phrasing cost a point, but nothing is redundant.

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 single-required-param read-only tool with no output schema, the description fully compensates: it describes the reply format, ordering, content, unknown-id behavior, and mutation-safety context. There is no meaningful gap an agent would need to resolve elsewhere.

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 coverage is 100% — the id parameter already has a description, so baseline is 3. The description adds meaning beyond the schema by explaining what happens with an unknown id (a plain string reply, not an error), which affects how the agent interp rets the response for that 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?

States a specific verb + resource: 'walks one item's whole life by id, oldest first' with concrete content (every declare, revise, retraction; sequence number, revision hash, author). It clearly distinguishes itself from the sibling 'get' by explicitly saying get returns only the current version, so an agent can tell them apart instantly.

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?

Gives explicit routing guidance: 'Use get instead for only the current version' names the alternative and the condition selecting it. It also provides a concrete use case — 'read it before you revise or retract again' — telling the agent when to call this tool in a workflow.

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