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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the agent knows this overwrites user data. The description adds the content/patch exclusivity and the read-tasks-first workflow cue, but does not itself say that a full content send is irreversible or what happens to prior plan text. With the safety profile carried by annotations, this is adequate but not 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 doing distinct work — purpose, parameter interaction rule, then prerequisite — with the primary verb and resource front-loaded. No filler.

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?

An output schema exists so return values need not be explained, and annotations cover the destructive/read-only profile. Combined with the mutual-exclusion rule and the read-tasks-first precondition, an agent has everything needed to call this correctly.

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 baseline is 3. The description earns an extra point by stating a cross-parameter constraint the schema never encodes: content and patch are mutually exclusive, and title composes with either. Omission of the date parameter costs nothing since the schema documents it fully.

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 concrete verb pair (write/edit) and a specific resource (the user's daily plan), plus the three operative modes (whole-content, patch, title-only rename). It is trivially distinguishable from view_plan (read) and from save_task/save_list (different resources) without opening any schema.

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 selection rules: content XOR patch ('not both'), title usable with either or alone, and a prerequisite ('Read the user's tasks first for context'). Nothing about how to choose between the write paths is left to inference.

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