Configure API credentials

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

Annotations declare a non-read-only, idempotent, non-destructive write; the description adds real context beyond that: values land in a 0600 file in the user config directory and never in a project, and empty strings delete a credential. It does not explain partial-update behavior (whether supplying one key preserves the other fifteen) or whether values are validated, which matters for a 16-field secret store.

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?

Four short sentences, zero padding, ordered from purpose to invocation modes to storage location to deletion. The most decision-relevant information (which mode to call) is front-loaded.

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 16-parameter, no-output-schema configuration writer, the description covers invocation modes, storage location, permissions and removal. It leaves the save semantics ambiguous (merge vs. overwrite of untouched keys) and never points at setup_status, which the schema itself references for signup walkthroughs.

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 description coverage is 50%, so the schema carries much of the burden via titles and per-key descriptions. The description contributes a global per-parameter rule the schema never states — an empty string removes that credential — which is meaningful semantics above the baseline.

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 ('Store API credentials for this server') and enumerates the three distinct invocation modes (no args = prompt, args = save given values, empty string = remove). It does not name or differentiate itself from the sibling setup_status, which is the one tool an agent could plausibly confuse it with, so it stops short of full sibling differentiation.

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 explicit for each mode: call with no arguments to prompt the user, call with arguments when the user has already supplied values, pass an empty string to delete. No alternatives or exclusions are named relative to setup_status/setup_status-style tools, so it gives clear context but no comparative routing.

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