Log progress

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

With no annotations, the description carries the full burden, and it does disclose non-obvious merge semantics: completedStep is relocated from nextSteps to completed on text match, and lists are appended without duplicates. It does not say where the data is persisted, whether non-list fields are overwritten, or what the call returns, leaving some behavioral gaps.

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?

Three tight sentences with zero filler; the invocation-frequency rule is front-loaded ahead of the merge mechanics, and every sentence conveys information an agent needs.

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 nine-parameter write tool with no annotations and no output schema, the description covers timing and merge behavior but omits what the call returns, where the checkpoint is stored, and how it relates to the other eight handoff tools. Adequate but with clear gaps.

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 already 89%, so baseline is 3, but the description adds genuine semantics the schema lacks: how completedStep and nextSteps interact and the append/dedupe rule applied to list parameters. It adds no field-level detail for status, decisions, tests, or changedFiles beyond what the schema states.

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 identifies the tool as a 'cheap, frequent checkpoint' that records step progress, which is a specific enough resource/action for an agent to understand. However, it never names or contrasts itself against siblings like save_handoff or update_handoff, which is the main ambiguity given nine closely related handoff tools.

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?

'Call after EVERY meaningful step, because a usage limit can end your session at any time' gives an explicit trigger and rationale for invocation frequency. It lacks any when-not guidance or a pointer to an alternative sibling for heavier or final-state persistence.

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