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

The description goes far beyond the readOnlyHint annotation by detailing the exact output structure: the `speakers` array fields, null handling (say nothing rather than filling gaps), and the critical distinction that `role` is a speaker-level note, not a session moderator. It also explains the `when` parameter semantics. This provides actionable guidance for interpreting results correctly.

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 long but dense with necessary information because there is no output schema. It front-loads the core purpose, then explains `when`, then details the speaker structure. Each sentence serves a purpose, particularly the role clarification and null handling. It is appropriately sized for the complexity, though slightly dense.

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 complex nested return structure and no output schema, the description covers all essential aspects: agenda contents, speaker fields, null semantics, and the `when` filter. It is complete for an agent to select and invoke correctly, and to interpret results without surprises. The readOnlyHint covers safety, and the description fills the rest.

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 baseline is 3. The description adds explicit meaning to the `when` parameter (all, today, now, date) and clarifies the default, which is valuable. For `eventIdOrSlug`, the schema already provides detailed guidance, so the description adds nothing new there. The extra `when` detail raises it to a 4.

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 it returns 'Agenda sessions and performances with their times', which is a specific verb+resource definition. It distinguishes from siblings like events_list (lists events) and events_get (gets event details) by focusing on the agenda/lineup within an event. The title 'Get the agenda or lineup' reinforces this.

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 explains the `when` parameter and its values, giving context on how to filter. However, it does not explicitly mention when to use this tool vs alternatives like events_speakers or events_speaker_detail, nor does it state any exclusions. The purpose is clear enough to infer usage, but explicit comparison is missing.

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