set_text_variable

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

With no annotations, the description carries the full behavioral burden. It does disclose one genuinely useful trait beyond the schema: the operation merges with existing variables rather than clearing them. However, it says nothing about overwrite semantics for an existing name, whether the change persists to disk or needs a save, or any project-open prerequisites.

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?

The core behavior is front-loaded in a single sentence, followed by brief per-argument notes with no filler. It is appropriately sized for a two-parameter setter, with only mild redundancy between the sentence and the Args block.

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 two-parameter mutation tool with no annotations and an existing output schema, the definition covers purpose, merge semantics, and both parameters. It still leaves open whether values persist across sessions or require a save step, and whether an existing name is silently overwritten, which are gaps for a setter with zero annotation coverage.

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: both parameters are explained, and the ${name} reference syntax is information the schema does not provide at all. This is precisely the kind of added meaning the schema lacks, though it stops short of format or length constraints.

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?

The description states a specific verb+resource ('Set (or add) one project text variable') and pins the scope to a single variable. It implicitly distinguishes itself from sibling readers like get_text_variables or expand_text, though it never names an alternative explicitly. An agent can tell what the tool does without opening the 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?

Usage is only implied through the phrase 'merging with existing variables', which tells the agent this is additive rather than a full replacement. There is no explicit when-to-use or when-not-to-use guidance relative to siblings such as get_text_variables, expand_text, or set_title_block.

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