update_manual_crypto

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

The annotation only declares idempotency, so the description adds useful behavioral context: the symbol cannot be changed and at least one updatable field is required. The description does not overstate side effects and aligns with the schema's manual/synced distinction.

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, front-loaded sentences state the operation, the precondition, and the key limitation. Every sentence earns its place, and there is no repetition of schema details or filler.

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 five-parameter update tool with no output schema, the description plus schema covers the essential invocation requirements: what to update, what fields are needed, and what cannot be changed. It omits return-value details, but that is a minor gap given the strong schema and the availability of sibling retrieval tools.

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?

Since schema description coverage is 100%, the schema already documents each parameter well. The description adds meaning beyond the schema by stating the 'at least one of' constraint and the immutability of the symbol, neither of which is captured in the JSON Schema required list.

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 opens with a specific verb and resource, 'Update a manually-managed crypto balance,' which clearly distinguishes this from create/delete/get siblings. It also limits scope to manually-managed balances, so there is little ambiguity about which crypto entity it targets.

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?

It provides a clear precondition ('At least one of name, display_name, institution_name, or balance must be supplied') and an exclusion (synced balances cannot be updated), which prevents invalid calls. It does not explicitly direct the agent to an alternative tool for creating or updating synced crypto balances, so it falls just short of a 5.

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