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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the bar is lower. The description adds genuinely useful data semantics beyond the annotations: amounts are bare numbers with no currency, and get_organization_settings must be called to interpret them. This is real behavioral context the schema 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?

Three short sentences, efficiently front-loaded with the core action before the currency caveat. The middle sentence about site/building resolution is arguably load-bearing on the wrong tool and costs a little sharpness.

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 single-parameter read with full annotation coverage and no output schema, the description is nearly complete: it covers what is fetched, the scope, and the one non-obvious return-value quirk (unitless amounts). Nothing critical is missing for correct invocation.

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?

Only one parameter with 100% schema description coverage, so the baseline is 3. The description adds nothing about the id beyond 'by ID', and the site_id/building_id reference describes parameters that don't exist on this tool, which adds noise rather than 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?

States a specific verb and resource with scope: 'Get a single annual funding budget by ID.' The word 'annual funding' distinguishes it from sibling budget tools like get_project_budget_item and list_budgets, though it never names those siblings explicitly.

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 routing hints (use list_sites/list_buildings to resolve IDs, call get_organization_settings for currency), but the site_id/building_id advice doesn't apply to this tool whose only parameter is the budget id, which is confusing. It never says when to use this versus list_budgets or get_project_budget_item directly.

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