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

Annotations already declare this a non-destructive, idempotent write. The description adds something annotations cannot express: that setting done=true cascades and also completes the linked path step. It still doesn't say whether 'change links' adds, replaces, or removes links, which is the one behavioral gap that matters for a mutation.

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 sentence, front-loaded with the verb and resource, with the mutable facets listed in a tight parallel enumeration and the higher-risk cascade note placed last. No filler whatsoever.

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 10-parameter mutation tool with no output schema, the description covers the intent of the common edits and one important cascade. It doesn't cover whether unspecified fields are left untouched, how link identifiers relate to one another, or what the itemId refers to, so an agent still has to guess at the mechanics.

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 only 10% across 10 params, so the description must compensate. It does map plain language onto roughly half of them (done, title via 'rename', estimateMin via 'estimate', area, isMainStep via 'main step'), but itemId, stepId, leverId, projectId and the partial-update semantics are unaddressed in both schema and description.

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 ('Change one plan item') plus resource and then enumerates the exact editable facets: done state, title, estimate, area, links, main-step flag. It distinguishes itself from siblings only implicitly, though — edit_step and edit_milestone exist and nothing here says how a plan item differs from those.

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?

No when-to-use guidance, no prerequisites, and no routing to alternatives such as edit_step, edit_milestone, delete_plan_item, or set_plan. The only conditional statement ('done=true also completes its linked path step') describes a side effect, not usage guidance.

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