Add prop

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

With annotations already declaring it a non-readonly, non-idempotent, non-destructive write, the description adds real context: presets seed defaults, any field can be overridden, and unlisted FDS 6.10.1 spray keys must be routed through `spray` using spr_upsert_spray_profile.prop names. It does not say what happens on a duplicate id, which is the main residual gap.

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 preset meanings, then the spray-routing rule. Dense but each sentence carries information; the trailing '[bulc-mcp rules] DEVC-009 …' fragment is somewhat cryptic but adds a pointer.

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 23-param mutation tool with no output schema, the description covers the two hardest concepts (preset semantics and spray-key routing). Missing only duplicate-id behavior and a note on units beyond what the schema already labels.

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 61% across 23 params, so the description must compensate and does: it enumerates the four quantity preset values with their meanings and explains the escape-hatch `spray` object. Many numeric physics fields (rti, beta, k_factor, bead_*) still rely on the schema's terse descriptions.

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 plus resource ('Add a &PROP device model') and immediately distinguishes it from siblings like update_prop/remove_prop by describing the preset-seeding behavior. An agent can tell what is created and how it is referenced (prop_id from devices).

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?

Explains the preset choice for quantity and points to bulc_knowledge_search for rules, which implies when the presets apply. However it never states when to reach for add_prop over add_device/add_heat_detector/add_sprinkler or when a preset vs full override is preferred, so alternatives are only implied.

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