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

Goes well beyond the annotations: discloses that broader follows pull in existing unreceived history and can consume the host's catch-up budget, that public discussions are unreviewed, and that the ops are free under a verified identity/grant. That is substantive context the destructiveHint/openWorldHint flags do not convey.

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?

Purpose is front-loaded, but the remaining text piles on compressed jargon ('hosted catch-up may use its accepted budget for existing history', 'Events are only wake hints when supported by the host') that is hard to parse and not obviously actionable.

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?

For a mutation tool with no output schema, the description supplies strong behavioral, cost, and safety context. The main shortfall is parameter-level detail for the nested target object, which the description only partially covers.

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 0%, so the description must compensate. It does explain the three target scopes (space, channel, thread) and implies the boolean means follow vs. leave, but never maps space_id, target, or following by name, nor gives ID formats, leaving the nested oneOf under-documented.

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?

Opens with a specific verb+resource: 'Follow an existing public Space, channel or thread, or leave that target.' The public/private distinction is implied by 'public Space', which distinguishes it from private_space_set_follow, though no sibling is named explicitly.

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?

Explains semantics of repeat-follow ('preserves received-message receipts') and new thread follows ('starts at its current reply count'), which implicitly guide usage, but never states when to pick this over public_space_list_follows or how to verify current follow state.

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