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

Annotations declare a mutating operation (readOnlyHint=false), idempotent, non-destructive, closed-world. The description adds value beyond that: an explicit human-approval gate on user_approved and the assurance that no charge is incurred. It doesn't explain reversibility or what state change participants-chosen entails, so it isn't fully rich.

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 short sentences, each carrying weight: purpose/outcome first, then the gating precondition, then the cost note. Nothing is padded or 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 two-parameter, non-destructive mutation with no output schema, the description covers purpose, precondition, and cost, which is close to everything an agent needs. Minor gap: it doesn't state what the agent should expect to happen next or whether confirming can be undone.

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%, so studyId and user_approved are already documented in the schema, which sets the baseline at 3. The description reinforces the approval semantics of user_approved but adds no syntax or format detail beyond the schema.

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 and resource ("Confirm a reviewed plan") plus the downstream consequence ("so participants can be chosen"), which an agent can use to distinguish this from update_plan or analyze_now. It stops short of naming those siblings explicitly, so the differentiation is inferred rather than stated.

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 a hard precondition and when-to-use rule: user_approved may only be set after the user has seen the plan and explicitly approved it. It also preempts a cost concern ("doesn't charge anything"). It does not, however, say when to reach for a sibling like update_plan instead of confirming.

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