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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so the safety profile is covered. The description adds only the prerequisite-tool guidance; it says nothing about duplicate-title behavior, validation failures, or what a successful call produces — gaps that matter given idempotentHint=false.

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?

Two tight sentences with zero filler. The core action is front-loaded and the prerequisites follow, with no redundant restatement.

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 simple three-parameter create with full schema coverage and annotations, the description covers the action and the preconditions well. The one real gap is return behavior — there is no output schema, and the description never says what the call yields (e.g., the created institution and its ID).

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 all three parameters are already documented, including the 'e.g. nzd, usd' example and the list_currencies pointer. The description merely restates that title and currency code are required, adding nothing the schema does not already say, so baseline 3 applies.

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 ('Creates a new financial institution') with the scoping qualifier 'for the given user.' This clearly separates it from delete_institution, update_institution, and get_institution by the create verb, 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?

Explicitly routes the agent to prerequisite tools: get_current_user for the user ID and list_currencies for valid currency codes. It gives clear context for building a valid call, but offers no exclusion guidance (e.g., when to update_institution instead of creating a duplicate).

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