Update control

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is known. The description adds little beyond that: it does not clarify whether this is a partial merge (unspecified fields preserved) or a full replace, which is the critical behavioral question for a 17-field update.

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?

Front-loaded with the core purpose in the first clause, and the two sentences are economical. The trailing '[bulc-mcp rules] DEVC-004, DEVC-006 — bulc_knowledge_search <id>' is cryptic and slightly disrupts the otherwise clean structure.

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?

A mutation tool with 17 params, 6% schema coverage, and no output schema needs much more than this. The description omits which fields are meaningful, whether updates merge or replace, and any return/validation behavior, leaving substantial responsibility on annotations that only cover the safety profile.

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 only 6% — 16 of 17 parameters (n, delay, latch, ramp_id, gains, on_bound, etc.) are completely undocumented. The description's 'Any field of add_control can be changed' only defers field meaning to another tool rather than explaining it, so it fails to compensate for the coverage gap.

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 an existing CTRL by ID') and distinguishes itself from sibling add_control/remove_control by framing it as modification of an existing object. 'CTRL' is FDS jargon left unexplained, but the reference to add_control's field set gives the agent a concrete anchor.

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 implied — update an existing control rather than add or remove one — and the rule pointer to bulc_knowledge_search hints at a compliance context, but no explicit when-to-use/when-not or named alternative is given. The agent must infer the update-vs-add boundary.

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