Plan a Meta catalog item update

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

Beyond the readOnlyHint annotation, it discloses that the tool reads the item first to capture a complete rollback snapshot, validates locally, and returns a signed plan with confirmation_token and confirm. These are operationally critical traits an agent could not infer from 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?

Two dense sentences, front-loaded with the 'writes nothing' safety framing, with parentheticals carrying secondary details. No wasted text.

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?

With no output schema, the description correctly explains the return value (signed plan with confirmation_token and confirm) and the follow-up tool. For a 7-param planning tool this is complete.

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 the schema already documents minor-unit semantics, enums, and 'empty keeps it' behavior. The description's parenthetical field list (price, sale price, availability, stock) restates schema content without adding format detail, so the baseline 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?

States a specific verb and scope — 'PLAN (writes nothing): update one Meta catalog product item' — plus the mutable fields in parentheses. It clearly distinguishes itself from the sibling apply tool (meta_apply) that actually performs the write.

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 workflow: plan here, then apply with meta_apply after the user agrees, and an extra precondition for price changes ('a price change also needs google-ecommerce-mcp approve'). Alternatives and conditions are both named.

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