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

Adds real context beyond the annotations: this is a full-replacement (PUT) operation where 'the previous values are overwritten', which sharpens the destructiveHint=true annotation into concrete behavior. It doesn't cover auth requirements or field-level validation, keeping it from a 5.

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 tight sentences, front-loaded with the replacement semantics and the overwrite warning, with the id-sourcing hint last. No wasted words.

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 an 8-param, nested-object, no-output-schema mutation tool, the description covers the key gotcha (full replacement) and id sourcing. Minor gaps remain around auth/permission needs and rejection of unknown fields, but the essentials are present.

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 coverage is 100%, so the baseline is 3. The description adds meaningful parameter semantics by framing all fields as a full payload and enumerating the categories (name, trigger, action, dates) that must be sent together, reinforcing how the required fields must be used.

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 (Replace/update) and resource (a rule) plus the fields touched: name, trigger, action, dates. It is clearly distinguishable from create_spotlight_rule and delete_spotlight_rule, though it doesn't explicitly name those siblings.

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 the crucial usage rule ('Send the whole rule, not only the changed part') and routes the agent to list_spotlight_rules to obtain the id. It stops short of explicitly contrasting with create/delete, but the context is clear.

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