Get direct debit

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond that – no auth requirements, no not-found/error behavior, no indication of what is returned, despite openWorldHint implying external data may not exist.

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?

A single short sentence, front-loaded with the verb and resource and free of padding. It is efficient, though the extreme brevity leaves no room for the routing guidance an agent would benefit from.

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 single-parameter read tool with full schema coverage and annotations covering safety, the description is minimally adequate. It omits return-shape expectations and error handling, which for an openWorldHint tool that may fail to find a mandate would be useful.

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?

With a single parameter and 100% schema description coverage, the schema already documents mandateUid. The description does not add format, sourcing, or validation meaning beyond the schema, so the baseline of 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?

The description states a verb (Gets) and resource (direct debit mandate) plus cardinality (one), which is more than a bare restatement of the title. However, it is nearly a tautology against the title 'Get direct debit' and gives no hint of how it differs from the sibling list_direct_debit_mandates beyond the word 'one'.

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?

There is no when-to-use guidance, no mention of alternatives such as list_direct_debit_mandates, and no statement of prerequisites (e.g. that a valid mandateUid must already be known). The agent must infer everything from the sibling name.

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