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 that reading changes nothing, spends no quota, works on a stopped account, that unknown sections return the start page plus list rather than an error, that "whats_new" is newest-first with an optional since, and that lane_note appears for account-specific advice. This is exactly the behavioral context an agent needs and cannot infer from structured fields.

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 the critical first-call instruction, and nearly every clause adds operative detail. It is on the long side and the unknown-section fallback is restated from the schema, so a small amount of redundancy keeps it from a 5.

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 two-parameter, no-annotation, no-output-schema tool, the description covers everything: when to call, what the return contains (text, sections, lane_note), fallback behavior, and the cost/read-only profile. Nothing needed to invoke it correctly 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 100%, so the baseline is 3, but the description goes further by explaining the semantics of unknown section values (fallback to start plus list), the meaning of lane_note relative to the section text, and the newest-first ordering that qualifies "since" is not in the schema.

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 concrete verb and resource ("Read the switchboard's operating manual, one section at a time") and frames the tool as the documentation entry point, which no sibling tool competes with. An agent instantly knows this is a read-the-docs call, not an action on intents or messages.

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 explicit timing guidance (call with "start" before first use of any other tool and before asking the human where they are) plus a general trigger rule (fetch a section whenever you meet something you do not know) with concrete examples. The "before you ask your human" instruction is a genuine ordering constraint that no other tool supplies.

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