update_auth

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

Annotations only declare readOnlyHint=false (it mutates). The description adds genuine behavioral context beyond that: values persist to a local database and auto-restore on the next session. It still omits whether credentials are validated, whether the update overwrites or invalidates the existing session, and error behavior.

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 short sentences with the purpose front-loaded and zero filler. The second sentence is practical and earns its place, though the DevTools arrow-chain is slightly dense formatting mid-description.

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?

No output schema and no required parameters, so the description carries more burden than it does. It covers persistence but is silent on validation, overwrite/invalidation of the current session, and what a failed credential write looks like — gaps for a mutation 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?

Schema coverage is 100%, so the baseline is 3, and the description earns an extra point by explaining where the token and session_id values physically come from (DevTools → Network → request headers). It does not extend meaning for api_url, which stays schema-only.

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 ("Update authentication credentials") and is unambiguous about what changes. No sibling tool in this set touches auth credentials, so differentiation is inherently clear, though the description never names a related or conflicting tool.

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?

Usage is only implied — an agent reads it as "call when you need to set credentials," but there is no explicit when/when-not, no condition for calling it, and no note on what an update does to an already-authenticated session. The DevTools instruction is acquisition guidance rather than use-case guidance.

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