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

Annotations already declare readOnlyHint=trueainer and idempotentHint=true, indicating no side effects. The description adds value by explicitly stating it does not read the calendar store, which is a key behavioral trait beyond the annotations. It also implies it requires pre-fetched events, adding necessary context for correct invocation.

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?

The description is extremely concise, consisting of two sentences. The purpose is front-loaded, then usage instructions are given, and a warning about side effects is included. No filler words; every sentence earns its place.

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?

The tool has an output schema, so the description need not explain return values. It provides the essential pipeline (search then render) and clarifies its read-only naturesame. Given the rich input schema and output schema, this is complete enough for an agent to execute correctly. A tiny gap is not explicitly saying the 'timezone' parameter is required, but the schema marks it required, so that's acceptable.

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 schema fully documents all parameters. The description adds some semantic context by specifying that 'from' and 'to' define the window and that 'events' must be pre-loaded, but it does not elaborate on the format or constraints beyond what the schema provides. Thus a baseline 3 is appropriate.

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?

The description clearly states the tool 'Show[s] a week or month agenda in the chat' with a specific verb and resource. It distinguishes itself from sibling render_event by focusing on week/month agendas, and implies it is distinct from data-fetching tools by noting it only renders.

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?

Provides explicit usage instructions: 'First call search_events with the same from and to, then pass view plus that window and events here.' This tells the agent the prerequisite call and exactly how to construct arguments, distinguishing it from search_events. It also states a boundary: 'This tool only renders; it does not read the calendar store,' preventing misuse.

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