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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely new context beyond annotations: the credit cost ('Flat 5 points per successful run') and the specific data fields returned, which helps the agent judge value.

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 compact sentences, front-loaded with the core action and return fields, with the cost note trailing. No wasted words.

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?

With no output schema, the description compensates by listing the returned fields (rating, followers, badges, legal name, location) and disclosing cost. Only minor gaps remain (no explicit sibling routing), so it is essentially complete for a single-parameter lookup.

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 coverage is 100% and the single 'seller' parameter is fully documented with an example in the schema. The description restates the accepted formats (key or URL) but adds no syntax or format detail beyond what the schema already provides, so the 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 ('Get one Newegg marketplace seller store'), specifies the accepted input forms ('store key or URL'), and enumerates the returned fields. This clearly distinguishes it from siblings like run_newegg_sellers_products (which lists products) and run_newegg_products.

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 phrase 'one ... seller store' implies a single-entity lookup rather than a search/list, which is useful context. However, it never explicitly states when to prefer this over run_newegg_sellers_products or other Newegg siblings, nor any prerequisites or exclusions. Usage is only implied.

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