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

Annotations already declare readOnlyHint=true and idempotentHint=false, so the safety profile is carried by structured data. The description adds useful return-shape context (router addresses, membership info) but discloses nothing beyond content—no note on scale, freshness, or why a read would be non-idempotent.

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 tight sentences with the core object of the call front-loaded and the type breakdown following immediately. No filler or restatement of the name.

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 carries the return-value burden and does so reasonably, naming the key categories plus router addresses and membership info. It is nearly complete for a zero-argument read tool, though the non-idempotent read hint is left unexplained.

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 takes zero parameters, so the schema baseline of 4 applies; there are no parameters whose semantics the description would need to elaborate.

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+resource ("Returns all vault public keys") and enumerates the three organizing categories (Asgard, Yggdrasil, inactive), which lets an agent distinguish it from single-vault siblings like get_vault or get_keysign_pubkey. It stops short of explicitly naming which sibling to prefer, so it is clear but not fully differentiated.

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 explains content but gives no when-to-use guidance, no conditions, and no reference to alternatives such as get_vault, get_vault_solvency, or list_asgard_vaults. An agent must infer the routing decision entirely on its own.

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