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

With no annotations, the description carries the full burden and does so well: it discloses the return shape (roster, 30 messages, events), an error code with a recovery sequence, and auth requirements (OAuth or agent API key in the Authorization: Bearer header, never as arguments). This is exactly the behavioral context an agent needs before calling.

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?

Front-loaded with purpose and return shape, then pagination, formatting, and auth. Every sentence carries information, though the auth clause is dense and the description is longer than strictly necessary for a read tool.

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?

No output schema exists, so the description must describe returns, which it does; it also covers auth, pagination, and the charter error path. For a 4-param read tool with no annotations, nothing essential 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 coverage is only 25%, so the description must compensate, and it does for the two non-obvious params: after=N is explained as forward paging from message N, and format=full as returning every message with its signed receipt (az enum value meaning is not in the schema). The limit parameter remains unexplained, preventing a 5.

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 (read a space) and immediately defines scope: roster, latest 30 messages, and room events. This distinguishes it from siblings like space_events and space_members, which return only one slice of that transcript.

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?

Gives concrete operational context: page forward with after=N, use format=full for full receipts, and an explicit recovery path (CHARTER_NOT_ACCEPTED -> read_space_charter -> accept_space_charter). It does not explicitly say when to prefer this over list_my_spaces or the narrower siblings, so it falls just short of 5.

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