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

Annotations only flag the mutation as non-destructive and open-world; the description adds substantive behavior: the change covers the trip 'with all its steps', followers retain visibility 'through the secret link', and the call requires explicit user confirmation plus a Cotlet API key with app access. That is exactly the kind of side-effect, reach, and auth context annotations cannot express.

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?

The purpose is front-loaded in the first two sentences with no wasted wording there. The trailing confirmation and API-key sentences read as policy boilerplate appended to the description, slightly diluting an otherwise tight definition.

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 mutation with no output schema, the description covers scope, confirmation policy, and auth requirements, which is enough to call it correctly. It stops short of noting reversibility or what a re-set to the previous level looks like, but 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 description coverage is 100% — both trip_id ('Trip ID from list_trips') and the privacy enum are fully documented in the schema. The description repeats the three privacy values but adds no format or sourcing detail beyond what the schema already provides, so the 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 ('Sets the privacy level of one trip') and enumerates the exact domain of values (Only me, Followers, Everyone). The scope is unambiguous — one trip, all its steps — so an agent can distinguish it from the other polarsteps trip/step tools without opening the schema.

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 real usage context: 'By default you confirm each call; you can switch that off for this tool' and 'Reaches other people: confirm with the user before each call', plus the auth prerequisite. It does not name alternatives, but no competing privacy tool exists among the siblings, so the omission is minor.

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