sch_place_dblib_component

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 declares the mutation (part built by Altium and dropped at x/y), the non-interactive behavior, and a hard precondition with a refusal path ("The call refuses before touching the sheet"). It also explains what database_linked and lib_reference read back. It stops short of stating undo/persistence semantics or what happens to the current selection.

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 action, then prerequisites, then the anti-pattern, then args/returns — a sensible reading order with no filler sentences. It runs long, and some of the Args/Returns text restates what the schema already lists, which costs a point.

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 9-parameter, 5-required mutating tool with no annotations, it covers purpose, prerequisites, failure modes, and even return-field semantics (including the part_id above part_count edge case) despite an output schema existing. An agent has everything needed to call it correctly or know why it will be refused.

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 0%, so the description must compensate, and it does for all nine parameters: it clarifies that table must be one the DbLib declares, that key is the value from a lib_dblib_search result, that x/y are in mils, that rotation is limited to 0/90/180/270, and that part_id is 1-based (A) with a default when omitted. This meaningfully exceeds the bare titles in the schema.

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 ("Place one database library (DbLib) part on a schematic sheet") and immediately narrows scope to .SchDoc targets. It explicitly separates itself from both the non-DbLib placement route and from design_execute_plan, so an agent can distinguish it without opening a schema.

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?

Gives an explicit when-not ("Do not draw a schematic part by part with this... this is for adding a part a person picked from their company library") and names the alternative (design_execute_plan). What's missing is differentiation from the closest siblings in the catalog, sch_place_components and sch_place_vault_components, which an agent could equally reach for.

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