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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description does add real value beyond them: the "newest first" ordering, the exact result shape, and the fact that results come "with their buckets and allowance." It stays silent on result volume behavior and the pagination mechanics, which are only inferable from the schema's cursor field.

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, zero filler, front-loaded with the core action and result shape before the filter and entry-point cues. The parenthetical field list is dense but earns its place since there is no output schema.

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 compensates by naming the six returned fields plus the bucket/allowance metadata. Ordering, both filters, and the entry-point recommendation are all present, which is everything an agent needs to call this list tool 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 the schema already documents limit, query, bucket, and cursor thoroughly. The description reinforces query ("searches titles and contents") and bucket ("keeps to one") but adds nothing on limit or the cursor/"More:" pagination contract. Baseline 3 is appropriate when the schema carries the weight.

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 ("List the user's Sixteen Bridges bubbles") and even enumerates the returned fields, so the agent knows exactly what comes back. "Start here" hints at its role as the entry point among the thirteen siblings, but it never explicitly distinguishes itself from near-neighbors like sixteenbridges_get_bubble or sixteenbridges_list_deleted_bubbles.

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?

"Start here" establishes it as the default entry point and the two filter clauses (query searches titles and contents; bucket keeps to one) tell the agent how to narrow results. What's missing is an explicit exclusion — nothing says when to prefer get_bubble for a single item or list_deleted_bubbles for trash.

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