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

Annotations already include readOnlyHint=true, so the agent knows this is a safe read. The description adds value by specifying the output categories (earned by tools, purchased, promotional), but it does not disclose other behaviors like authentication needs or response details. This is acceptable but not exceptional given the simple nature of the tool.

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, well-structured sentence that front-loads the main concept and adds relevant detail. Every word contributes meaning, with no wasted text.

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 zero-parameter read-only tool with no output schema, the description fully communicates what the agent will receive: balance, recent activity, and a provenance breakdown. Nothing critical is missing for selecting and invoking this tool.

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?

The tool has zero parameters, so the description has no obligation to explain parameter usage. It still clarifies what the returned data will include, which is helpful for invoking the tool correctly. Baseline for 0 params is 4, which fits here.

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 clearly identifies the resource (MESH credit balance) and the kind of information returned (balance, activity, provenance breakdown), distinguishing it from sibling mesh_* tools. It lacks an explicit verb like 'get' or 'retrieve', but the intent is unambiguous.

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 implies when to use this tool: to view your MESH credits and understand their source. It provides clear context but does not explicitly exclude alternatives or name sibling tools, so it is slightly below a 5.

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