Overview of a city’s events across a month

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

Beyond the annotations (readOnlyHint, openWorldHint, idempotentHint), the description discloses critical behavioral traits: 'events is a preview while total is the real count,' the calendar shows at most four listings per day, and the national hub has no local calendar. It also clarifies the read-only nature, matching annotations without contradiction.

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?

Four sentences, each serving a distinct purpose: purpose, parameter instruction, behavioral caveat with alternative, and use-case summary. The information is front-loaded with the core purpose and the critical preview/total distinction appears early. No filler or redundancy.

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?

Despite no output schema, the description sufficiently explains the response structure ('for each day, the true number of listings and a short preview') and clarifies the meaning of the fields. It covers limitations, defaults implicitly via schema, and provides routing to the correct sibling for deeper detail. An agent has everything needed to call this tool 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%, with both site and month fully documented including aliases, pattern, and default. The description's mention of 'Pass the site key' adds no substantial meaning beyond the schema, so the baseline of 3 applies. It does reinforce cross-tool reference to otc_list_sites, but that is already in the schema.

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 states a specific verb and resource: 'Day-by-day overview of a whole month from a city’s events calendar.' It clearly differentiates from the sibling otc_list_events by noting the month-level aggregation and explicitly pointing to the alternative for a single day's full schedule. The scope and output shape ('true number of listings and a short preview') are unambiguous.

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 gives explicit when-to-use guidance: 'Use this to find the busiest days or scan a month at a glance.' It also states when not to use it, pointing users to otc_list_events for a specific date and warning that the national hub is not a valid site. It further directs users to otc_list_sites for obtaining the site key, covering both prerequisites and alternatives.

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