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

Annotations only declare the generic mutation profile (readOnly=false, destructive=false, idempotent=false). The description goes well beyond that: it discloses the required scope, the 409 conflict on duplicate slots, and the fact that site_id/building_id are ignored by the tab.

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?

Front-loads purpose, then scope, then constraints in a logical order. It is dense rather than padded, though the slot rule is restated in two places, costing a little tightness.

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?

No output schema, but for a create tool the description covers scope, required fields, uniqueness constraints, and the failure mode (409). An agent has everything needed to invoke it 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?

Schema coverage is 100%, so the schema already documents every parameter including the 'Not read by the Budget tab' notes. The description restates the required fields and slot semantics but adds little syntax or format detail beyond the schema.

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 ('Set an annual funding budget') and anchors it to a concrete surface ('as the dashboard Budget tab does'). This clearly separates it from siblings like create_project_budget_item or create_expense.

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 the precondition ('Requires budgets:write scope') and the granularity rule (one row per year and funding source, no site/building splitting). It lacks an explicit 'use X instead' pointer to a sibling, but the context is otherwise clear.

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