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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: result cap of 20, soonest-first ordering, the 30-day default horizon with a 180 max, and the fact that free text is analyst notes rather than raw data.

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 tight sentences with zero filler, front-loading what the tool returns before covering the optional filters and the nature of the text field.

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 does the work of describing the return shape: capped at 20, sorted soonest-first, text field is analyst notes. Only minor ambiguity remains (what 'the Book' encompasses, how the horizon interacts with the cap).

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 only 50% (the days parameter has no schema description), and the description compensates by stating that days is an optional horizon defaulting to 30 with a max of 180, plus that token is an optional slug filter. That meaningfully exceeds what the schema alone conveys.

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 resource (upcoming dated catalysts) and enumerates the event types (unlocks, emission steps, votes, launches), which lets an agent recognize the tool's domain quickly. It does not, however, explicitly distinguish itself from plausible siblings like tc_alerts or tc_moves, so it stops short of a 5.

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?

The description implies the usage context (get upcoming dated events, optionally narrowed by token and horizon) and gives the horizon default of 30 days, but it never states when to prefer this over tc_alerts or other event-like siblings, nor any exclusions.

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