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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description focuses on what the annotations can't say: the response shape (header then Markdown content), the 30000-character page size, and the trailing next-offset. It stops short of naming the pagination field or saying what the header contains.

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?

Two sentences with no filler. The core purpose is front-loaded and the paging caveat follows logically, so an agent can stop reading after the first sentence for most calls.

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 no output schema, the description carries the burden of explaining the return value, and it does so at a useful level (header plus content, page size, next offset). It is not fully complete because the actual field names of the header and of the returned offset are left unspecified.

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 id, offset, and max_chars are already documented with patterns, defaults, and bounds. The description only restates the default page size, adding no new syntax or constraints beyond the schema; 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 ('Read one bubble') and immediately characterizes what a bubble is (short header plus Markdown content). It is clearly distinguishable from list_bubbles, which returns many bubbles, and from the mutation siblings.

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 paging sentence tells the agent exactly how to continue a partial read ('the reply ends with the offset to read next'), which is real usage guidance for the most common follow-up case. It does not, however, explicitly say when to prefer this over list_bubbles or note that the id comes from list_bubbles (that hint lives only in the schema).

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