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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, so the safety profile is known. The description adds that the contribution can optionally be mirrored as a personal transaction, but says nothing about whether contributions are additive/cumulative, reversible, or validated against the goal amount.

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 tightly written sentence with the core action front-loaded and no filler. Appropriate length for the operation, though minimal for a mutation with 4 parameters.

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 non-destructive mutation with no output schema and sparse schema coverage, the definition is thin: it doesn't say what the tool returns, how goal progress is affected, or what transactionDescription does when createTransaction is true.

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 only 25%, so the description must compensate. It clarifies the meaning of createTransaction ('also record... as a personal transaction'), which helps, but leaves transactionDescription and the semantics of amount against the goal target unexplained.

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 ('Add a contribution') and resource ('savings goal'), plus the optional side effect. An agent can distinguish it from create_goal/update_goal, though it doesn't explicitly name how it differs from create_personal_transaction despite overlapping behavior.

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?

No when-to-use, when-not-to-use, or alternatives are given. The phrase 'optionally recording it as a personal saving transaction' hints at a related sibling (create_personal_transaction) but never states when to prefer that route or whether prerequisites exist.

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