submit_icon_labels

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

With no annotations, the description carries the full burden and does so: it discloses the wide-reaching persistence ('written onto the glyph AND onto every place it is already drawn on the map, and every future sighting'), the atomicity guarantee ('applied whole or not at all'), and the failure mode (invalid key, blank name, or missing app_name returns a sentence rather than a partial write). These are exactly the side-effect and error semantics an agent needs for a mutation tool.

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 purpose, then parameter semantics, then persistence/atomicity/error behavior, then the reply — every clause adds information. It is a dense single paragraph with some run-on sentences and no visual structure, which costs a point but nothing is wasted.

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?

An output schema exists, so return values need not be spelled out, yet the description still frames them usefully ('how many glyphs and places were named and how many of that app's icons are still unnamed'). For a 2-param mutation tool with zero annotations and zero schema coverage, all decision-relevant context — sequencing, key semantics, persistence, atomicity, errors — is present.

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, and it does: it defines the labels key as 'the string annotate_icons printed for that cell, NOT the cell number' and the value as 'the name of the control, in the words a user would use for it' with concrete examples, plus app_name as 'the application annotate_icons reported'. This resolves the most likely ambiguity (key vs. cell index) that the bare object schema leaves open.

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+resource ('send back what the icons on an annotate_icons sheet are called') and explicitly positions itself as 'the second half of the round trip' relative to the annotate_icons sibling. An agent can distinguish this from annotate_icons and from the other siblings without opening either 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?

The sequencing guidance is explicit: this is the return half of the annotate_icons round trip, and the description even shows the downstream step ('target it by the name you gave it: {action:'click', target:{text:'Share'}}'). It does not state an explicit when-not-to-use or a named alternative for submitting labels differently, so it stops just short of a 5.

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