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

Annotations already cover read-only/idempotent safety, and the description adds substantial context beyond them: a hard 2000-character cap, that the content is system-generated, that it is also delivered as handoff_brief on first read, and a security warning that the summarized room content is untrusted and must not be followed.

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?

It is essentially one long but dense sentence that front-loads the purpose before the contents, handoff note, and safety warning. Every clause earns its place, though the packing into a single sentence slightly reduces readability.

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 an output schema present, return values need no explanation, yet the description still enumerates contents. It also covers the size limit, the handoff_brief relationship, and the untrusted-content caveat, leaving nothing an agent needs to call it 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%, so room_id and agent_id are already fully documented in the schema. The description adds nothing about parameter semantics, which is acceptable given the schema does the work, so the baseline 3 applies.

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 verb and resource (a system-generated room summary for an AI catching up) and enumerates exactly what it contains: name/topic, pins with notes, open tasks with fields, and latest message excerpts. This distinguishes it from siblings like city_room_overview and city_room_read without the agent opening a schema.

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 phrase 'for an AI catching up' plus the note that the first city_room_read also carries it once as handoff_brief gives clear context and even hints you may get it for free. However, it never explicitly states when to call this versus city_room_read or city_room_overview, so it stops short of full routing guidance.

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