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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by disclosing a downstream consequence: omitting total cost and currency corrupts the trip budget. It still says nothing about return shape, duplicate handling, or permission requirements.

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?

Three sentences, front-loaded with what the tool does, then the multi-option workflow, then the two hard constraints. No preamble, no repetition of the title, and every sentence carries a distinct instruction.

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 nested-object mutation tool with no output schema, the description covers purpose, workflow routing, a required-field constraint and a naming convention. Gaps remain around what is returned after the add and how duplicates or re-adds behave, but annotations carry the safety profile so nothing critical for invocation 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%, including detailed guidance on name hygiene, currency, dates and nested objects, so the baseline is 3. The description restates the cost/currency requirement and the 'keep name clean' rule, which reinforces but does not add syntactic or semantic detail beyond what the schema already provides.

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 ('Propose somewhere to stay at a destination') and enumerates the supported types (hotel, hostel, apartment, house, camping), which maps directly onto the type enum. It also situates the tool in a workflow by naming select_destination_option as the downstream step, so an agent can separate it from sibling add_* tools without opening a 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?

Explicitly tells the agent to add several options to the same destination for comparison and to route to select_destination_option once a choice is made — clear when-to-use and a named alternative. However, it never mentions the obvious edit path (update_destination_option) for correcting an existing option, so the guidance is one-directional rather than complete.

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