NEXO Brain

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

With no annotations provided, the description carries full burden for behavioral disclosure. While 'Update' implies a mutation operation, the description doesn't address important behavioral aspects: whether this requires specific permissions, if updates are reversible, what happens when optional parameters are omitted (do they clear existing values?), or any rate limits. The description states what can be updated but not how the update behaves.

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 appropriately concise with two sentences: a clear purpose statement followed by a parameter list. The structure is front-loaded with the core functionality. The Args section is organized but could be more integrated with the description text rather than appearing as a separate block.

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 mutation tool with 4 parameters, 0% schema coverage, no annotations, but with an output schema present, the description is minimally adequate. The presence of an output schema means the description doesn't need to explain return values, but it should provide more context about the update operation's behavior, error conditions, and relationship to other credential tools. It covers the basics but leaves important contextual gaps.

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 description includes an Args section that lists all 4 parameters with brief explanations. However, with 0% schema description coverage, this minimal documentation doesn't fully compensate. The explanations are basic ('Service name', 'Key name', 'New value', 'New notes') without clarifying what constitutes valid service/key names or the format/constraints for values and notes. The description adds some value but leaves significant gaps.

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 states the tool's purpose: 'Update a credential's value and/or notes.' It specifies the verb (update) and resource (credential) with the specific fields that can be modified. However, it doesn't explicitly differentiate from sibling tools like nexo_credential_create or nexo_credential_delete, which would be needed for a perfect score.

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 versus alternatives. There's no mention of prerequisites, when this should be used instead of nexo_credential_create or nexo_credential_delete, or any context about credential management workflows. The agent must infer usage from the tool name and description alone.

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