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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuinely new behavioral context that amounts are bare numbers with no currency attached and that currency_code must be fetched separately. That is exactly the kind of non-obvious trait that prevents a wrong answer downstream. It does not describe filtering default behavior (all rows when unfiltered), which keeps it off a 5.

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 short sentences, purpose first, filter surface second, the currency caveat last. No filler and nothing redundant with structured fields.

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 8 optional params, no output schema, and pagination already handled in the schema, the description covers what an agent needs to call it correctly and to interpret amounts. The one gap is not stating that an unfiltered call returns all cost rows across the org.

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 every parameter is already documented with type, enum, and date format; the description only restates the filter dimensions at a higher level. Baseline 3 is correct since the schema does the heavy lifting and the description adds no new parameter-level meaning.

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?

Specific verb+resource: 'List cost rows for infrastructure features', with the filterable dimensions enumerated. It does not explicitly distinguish itself from the sibling list_asset_costs, so the agent must infer that this one is scoped to infrastructure features rather than general assets.

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 clear usage context (filter by feature, work order, vendor, category, or cost date range) and mandates a follow-up call to get_organization_settings before stating currency. It stops short of naming exclusions or the sibling list_asset_costs as an alternative, so the sibling-selection question is left implicit.

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