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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds valuable behavioral details beyond those: 'it does not consume plan stops', 'empty=true means the account has no vehicles saved', 'A vehicle with no capacity means the account never set one, not that it carries nothing', and the note that one-run vehicles are not saved. These clarify return semantics and data interpretation, making the tool's behavior much more transparent.

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 description is dense but all sentences carry necessary information. It front-loads the core purpose, then covers side effects, empty states, capacity semantics, and unsaved vehicles. The main sentence is long with multiple parenthetical clauses, slightly reducing readability, but every part earns its place and there is no filler.

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?

Given the tool's zero parameters, read-only annotations, and the presence of an output schema, the description is exceptionally complete. It covers edge cases (empty account, null capacity), clarifies the relationship to optimize_routes and manage_catalog, and explains what is NOT included. An agent has everything needed to invoke and interpret this 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?

The tool has zero parameters and the schema coverage is 100%, so the baseline is 4. The description reinforces this with 'Takes no arguments' and explains that the catalog belongs to the connected account, which adds minimal but sufficient context. There is no parameter documentation burden to compensate for.

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?

The description clearly states the tool's function: 'List what the connected Vepathos account has saved: vehicles and fleets ... and depots'. It specifies the exact resource (catalog contents) and provides differentiating details about the IDs returned and their role in optimize_routes, distinguishing it from siblings like manage_catalog and optimize_routes.

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 description gives concrete usage context: it is read-only, takes no arguments, and does not consume plan stops. It also provides conditional guidance: when empty=true, ask the user and save via manage_catalog; vehicles for one run should be passed to optimize_routes. While it does not explicitly state 'use this instead of X', it clearly implies when this tool is appropriate and routes to alternatives for specific cases.

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