history

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

With no annotations, the description carries the full behavioral burden and does so thoroughly: 'Read-only; nothing is ever deleted from the log' explains durability and safety. It also discloses the unknown-id response ('no history for id X' is 'not an error') and the one-line-per-revision reply format.

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?

Every sentence earns its place: primary action, sibling alternative, behavioral guarantees, and output format. It is front-loaded with the core verb and resource, then strategically narrows scope and edge cases without any filler.

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, so the description's explicit mention of reply format ('one line per revision') and unknown-id handling fills the gap. It also covers retraction semantics and a pre-revision/retraction use case, making it complete for an agent to invoke safely and 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?

Schema description coverage is 100%, and the schema's description of id ('The id whose whole life to walk') already conveys meaning. The tool description reinforces the id's role but adds no new syntactic or format detail beyond that, so the baseline of 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?

Description states a specific verb and resource: 'walks one item's whole life by id, oldest first' and lists what is included (declare, revise, retraction with sequence number, revision hash, author). It also distinguishes from sibling get: 'Use get instead for only the current version.'

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?

Provides explicit alternative guidance: 'Use get instead for only the current version.' Also gives a concrete precondition: 'read it before you revise or retract again.' This clearly tells the agent when to choose history over get and when the history is still meaningful.

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