lib_add_symbol_text

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

With no annotations, the description carries the full load and does so: it explains that empty strings are refused rather than placed (and why), that font_size is Altium's font-manager number and deliberately not converted from mils, and how owner_part_id values 0/1..part_count behave. That is exactly the non-obvious behavioral context an agent can't get from the schema.

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 batching recommendation and the object type, then structured args with per-field notes. The font_size and owner_part_id explanations run long, but each is justified by a real risk (silent resizing, sub-part misassignment), so nothing reads as 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?

The output schema covers return values, and params are fully documented. The only gap is that it references 'the current symbol' without stating that a component must be selected first (e.g. via lib_set_current_component) — a prerequisite an agent could miss.

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%: the array's items are opaque objects with additionalProperties true, so the schema documents nothing. The description fully compensates by enumerating every field (text, x/y in mils, rotation with allowed values, font_size, font_name, bold/italic, owner_part_id) with types and defaults.

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 ('Add MANY body-text items to the current symbol in ONE call') and goes further by naming the underlying object type ('Altium ISch_Label') and its use cases (polarity marks, pin-group headings, NC annotations). This clearly separates it from lib_add_symbol_lines and lib_add_footprint_text.

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?

Explicitly says 'PREFER THIS over adding text one at a time (there is no singular variant)', which resolves the main batching decision. It also points to 'lib_add_pins' for the meaning of owner_part_id. It lacks any 'when not to use' note (e.g. lines vs. text), which keeps it below 5.

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