get_instance_setting

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

With no annotations, the description carries the full burden and does well: it discloses the two resolution paths (bridge-enabled effective value vs direct instance.cfg [General] read) and the null-on-missing-key outcome. What it omits is error behavior for an unknown id and whether the read is cached or live.

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 sentences, front-loaded with purpose, followed by conditional behavioral detail. No restatement of the title and no wasted filler.

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 two-parameter read with no annotations and no output schema, the description supplies the semantics an agent actually needs: what gets read, which source, and what null means. Only the undefined 'id' parameter and failure modes keep it from fully complete.

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 0%, so the description must compensate. It does explain 'key' meaningfully (a [General] key in instance.cfg, subject to override resolution), but 'id' is never defined — the agent must infer it is an instance identifier from the sibling set — and no key format or casing rules are given.

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 opens with a precise verb+resource+cardinality: 'Read one key from an instance's settings.' That distinguishes it implicitly from plural siblings like list_instance_settings and from the mutating set_instance_setting, though it never names those siblings or contrasts with get_settings/get_options.

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 by 'one key' vs the plural listing siblings. There is no explicit statement of when to prefer this over list_instance_settings, get_settings, or get_options, and no prerequisite guidance such as whether the instance must exist or be running.

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