ebay_update_custom_policy

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

Annotations already indicate this is a mutating operation (readOnlyHint: false) and idempotent (idempotentHint: true), but the description adds no behavioral context beyond the word 'Update'. It does not clarify whether the policy is fully replaced, partially merged, or what side effects occur.

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?

The description is a single, focused sentence with no filler or repetition. It is concise and front-loaded, though it is minimal enough that some useful context is sacrificed.

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 nested-object mutation tool with no output schema, the description is too thin. It does not explain whether policy.customPolicyId must match the top-level customPolicyId, whether updates are partial or full replacements, or how to distinguish this from related policy update tools. An agent could invoke this incorrectly without additional information.

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% for top-level parameters, so the baseline is 3. The description itself adds no parameter-level meaning; nested fields like policyType and the duplicated customPolicyId are not clarified, but the schema already provides basic descriptions.

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 clear verb ('Update') and a specific resource ('existing custom policy'), which distinguishes it from create/get custom policy tools. It is not a tautology and directly maps to the tool's name.

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?

The description provides no guidance on when to use this tool over alternatives such as ebay_create_custom_policy, ebay_get_custom_policy, or the other update policy tools. No prerequisites, exclusions, or conditional use cases are mentioned.

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