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

Annotations already mark this as read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond those hints: a hard safety ceiling of 50 records, no pagination, and the total/truncated fields that disclose omission. It also clarifies the calendar/timezone semantics, which is important for date-based queries. No contradiction with annotations.

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 tightly written sentences: the operation and scope, the behavioral ceiling and result disclosure, and the pointer to get_sermon for full text. Every sentence carries distinct value, and the most important constraint is front-loaded. No filler or repetition.

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?

Given the simple two-parameter schema, the presence of an output schema, and annotations that cover safety semantics, the description is complete. It explains the timezone/day scope, the optional church filter, the 50-record limit, the no-pagination behavior, the total/truncated indicators, and the follow-up tool for full text. Nothing essential for correct invocation is missing.

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 reinforces the date semantics ('Europe/Warsaw calendar day') and the optional church filter, but it does not add meaningful information beyond what the schema already documents. It neither hurts nor substantially improves parameter understanding.

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 ('List'), resource ('public sermons'), and scope ('start time falls on one selected Europe/Warsaw calendar day'), and explicitly distinguishes the tool from get_sermon by noting that full sermon text requires a different tool. It is immediately clear what this tool does and how it differs from at least one sibling.

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 clear usage context: list sermons by date, optionally filtered by church, with a hard cap of 50 records. It explicitly routes the agent to get_sermon when full text is needed. It does not mention when to prefer list_recent_sermons over this tool, but the date-scoped purpose is clear enough for most selection cases.

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