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

Annotations already establish this as a safe read (readOnlyHint=true), so the description only needs to add context — and it does, by defining the sign convention: positive means over-solvent, negative means under-solvent. That value-interpretation is exactly the kind of behavioral detail an agent cannot derive from the empty schema. It omits aggregation scope and any freshness/timing caveats, so not a 5.

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 sentences, front-loaded with the core behavior, followed by the sign convention and a one-line usage rationale. No filler or repetition.

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 parameters and no output schema, the description carries the burden for both behavior and return-value interpretation, and it handles the critical piece (what positive/negative amounts mean). It stops short of stating the scope of aggregation (all vaults vs. a subset) or which assets appear, which would make it fully self-contained.

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 schema declares zero parameters, so the baseline of 4 applies. There is nothing for the description to clarify about inputs, and it correctly does not invent any.

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 ('Returns aggregate vault solvency') plus the shape of the result ('per asset'), which clearly separates it from siblings like get_vault, get_vault_pubkeys, and get_tvl_history. An agent can tell what it gets without opening any schema.

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?

'Critical for monitoring vault health' implies the usage context but never states when to prefer this over alternatives such as get_vault or get_tvl_history, and offers no exclusions or prerequisites. Usage is inferable but not guided.

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